diff --git a/modules/core/context.js b/modules/core/context.js
index ed4bf64ef..0b54db23a 100644
--- a/modules/core/context.js
+++ b/modules/core/context.js
@@ -18,7 +18,7 @@ import { presetManager } from '../presets';
 import { rendererBackground, rendererFeatures, rendererMap, rendererPhotos } from '../renderer';
 import { services } from '../services';
 import { uiInit } from '../ui/init';
-import { utilKeybinding, utilRebind, utilStringQs } from '../util';
+import { utilKeybinding, utilRebind, utilStringQs, utilUnicodeCharsTruncated } from '../util';
 
 
 export function coreContext() {
@@ -196,6 +196,27 @@ export function coreContext() {
   context.maxCharsForTagValue = () => 255;
   context.maxCharsForRelationRole = () => 255;
 
+  function cleanOsmString(val, maxChars) {
+    // be lenient with input
+    if (val === undefined || val === null) {
+      val = '';
+    } else {
+      val = val.toString();
+    }
+
+    // remove whitespace
+    val = val.trim();
+
+    // use the canonical form of the string
+    if (val.normalize) val = val.normalize('NFC');
+
+    // trim to the number of allowed characters
+    return utilUnicodeCharsTruncated(val, maxChars);
+  }
+  context.cleanTagKey = (val) => cleanOsmString(val, context.maxCharsForTagKey());
+  context.cleanTagValue = (val) => cleanOsmString(val, context.maxCharsForTagValue());
+  context.cleanRelationRole = (val) => cleanOsmString(val, context.maxCharsForRelationRole());
+
 
   /* History */
   let _inIntro = false;
diff --git a/modules/ui/commit.js b/modules/ui/commit.js
index 246535dab..a0f494952 100644
--- a/modules/ui/commit.js
+++ b/modules/ui/commit.js
@@ -12,7 +12,7 @@ import { uiChangesetEditor } from './changeset_editor';
 import { uiSectionChanges } from './sections/changes';
 import { uiCommitWarnings } from './commit_warnings';
 import { uiSectionRawTagEditor } from './sections/raw_tag_editor';
-import { utilArrayGroupBy, utilRebind, utilUnicodeCharsTruncated, utilUniqueDomId } from '../util';
+import { utilArrayGroupBy, utilRebind, utilUniqueDomId } from '../util';
 import { utilDetect } from '../util/detect';
 
 
@@ -63,8 +63,6 @@ export function uiCommit(context) {
 
     function initChangeset() {
 
-        var tagCharLimit = context.maxCharsForTagValue();
-
         // expire stored comment, hashtags, source after cutoff datetime - #3947 #4899
         var commentDate = +prefs('commentDate') || 0;
         var currDate = Date.now();
@@ -92,9 +90,9 @@ export function uiCommit(context) {
         var detected = utilDetect();
         var tags = {
             comment: prefs('comment') || '',
-            created_by: utilUnicodeCharsTruncated('iD ' + context.version, tagCharLimit),
-            host: utilUnicodeCharsTruncated(detected.host, tagCharLimit),
-            locale: utilUnicodeCharsTruncated(localizer.localeCode(), tagCharLimit)
+            created_by: context.cleanTagValue('iD ' + context.version),
+            host: context.cleanTagValue(detected.host),
+            locale: context.cleanTagValue(localizer.localeCode())
         };
 
         // call findHashtags initially - this will remove stored
@@ -126,7 +124,7 @@ export function uiCommit(context) {
                 }
             });
 
-            tags.source = utilUnicodeCharsTruncated(sources.join(';'), tagCharLimit);
+            tags.source = context.cleanTagValue(sources.join(';'));
         }
 
         context.changeset = new osmChangeset({ tags: tags });
@@ -139,36 +137,34 @@ export function uiCommit(context) {
         var osm = context.connection();
         if (!osm) return;
 
-        var tagCharLimit = context.maxCharsForTagValue();
-
         var tags = Object.assign({}, context.changeset.tags);   // shallow copy
 
         // assign tags for imagery used
-        var imageryUsed = utilUnicodeCharsTruncated(context.history().imageryUsed().join(';'), tagCharLimit);
+        var imageryUsed = context.cleanTagValue(context.history().imageryUsed().join(';'));
         tags.imagery_used = imageryUsed || 'None';
 
         // assign tags for closed issues and notes
         var osmClosed = osm.getClosedIDs();
         var itemType;
         if (osmClosed.length) {
-            tags['closed:note'] = utilUnicodeCharsTruncated(osmClosed.join(';'), tagCharLimit);
+            tags['closed:note'] = context.cleanTagValue(osmClosed.join(';'));
         }
         if (services.keepRight) {
             var krClosed = services.keepRight.getClosedIDs();
             if (krClosed.length) {
-                tags['closed:keepright'] = utilUnicodeCharsTruncated(krClosed.join(';'), tagCharLimit);
+                tags['closed:keepright'] = context.cleanTagValue(krClosed.join(';'));
             }
         }
         if (services.improveOSM) {
             var iOsmClosed = services.improveOSM.getClosedCounts();
             for (itemType in iOsmClosed) {
-                tags['closed:improveosm:' + itemType] = utilUnicodeCharsTruncated(iOsmClosed[itemType].toString(), tagCharLimit);
+                tags['closed:improveosm:' + itemType] = context.cleanTagValue(iOsmClosed[itemType].toString());
             }
         }
         if (services.osmose) {
             var osmoseClosed = services.osmose.getClosedCounts();
             for (itemType in osmoseClosed) {
-                tags['closed:osmose:' + itemType] = utilUnicodeCharsTruncated(osmoseClosed[itemType].toString(), tagCharLimit);
+                tags['closed:osmose:' + itemType] = context.cleanTagValue(osmoseClosed[itemType].toString());
             }
         }
 
@@ -187,10 +183,10 @@ export function uiCommit(context) {
                     var issuesBySubtype = utilArrayGroupBy(issuesOfType, 'subtype');
                     for (var issueSubtype in issuesBySubtype) {
                         var issuesOfSubtype = issuesBySubtype[issueSubtype];
-                        tags[prefix + ':' + issueType + ':' + issueSubtype] = utilUnicodeCharsTruncated(issuesOfSubtype.length.toString(), tagCharLimit);
+                        tags[prefix + ':' + issueType + ':' + issueSubtype] = context.cleanTagValue(issuesOfSubtype.length.toString());
                     }
                 } else {
-                    tags[prefix + ':' + issueType] = utilUnicodeCharsTruncated(issuesOfType.length.toString(), tagCharLimit);
+                    tags[prefix + ':' + issueType] = context.cleanTagValue(issuesOfType.length.toString());
                 }
             }
         }
@@ -546,18 +542,16 @@ export function uiCommit(context) {
     function updateChangeset(changed, onInput) {
         var tags = Object.assign({}, context.changeset.tags);   // shallow copy
 
-        var tagCharLimit = context.maxCharsForTagValue();
-
         Object.keys(changed).forEach(function(k) {
             var v = changed[k];
-            k = utilUnicodeCharsTruncated(k.trim(), tagCharLimit);
+            k = context.cleanTagKey(k);
             if (readOnlyTags.indexOf(k) !== -1) return;
 
             if (k !== '' && v !== undefined) {
                 if (onInput) {
                     tags[k] = v;
                 } else {
-                    tags[k] = utilUnicodeCharsTruncated(v.trim(), tagCharLimit);
+                    tags[k] = context.cleanTagValue(v);
                 }
             } else {
                 delete tags[k];
@@ -569,7 +563,7 @@ export function uiCommit(context) {
             var commentOnly = changed.hasOwnProperty('comment') && (changed.comment !== '');
             var arr = findHashtags(tags, commentOnly);
             if (arr.length) {
-                tags.hashtags = utilUnicodeCharsTruncated(arr.join(';'), tagCharLimit);
+                tags.hashtags = context.cleanTagValue(arr.join(';'));
                 prefs('hashtags', tags.hashtags);
             } else {
                 delete tags.hashtags;
diff --git a/modules/ui/fields/access.js b/modules/ui/fields/access.js
index fcc346970..d7f4c8d6f 100644
--- a/modules/ui/fields/access.js
+++ b/modules/ui/fields/access.js
@@ -47,7 +47,6 @@ export function uiFieldAccess(field, context) {
             .attr('class', 'preset-input-access-wrap')
             .append('input')
             .attr('type', 'text')
-            .attr('maxlength', context.maxCharsForTagValue())
             .attr('class', function(d) { return 'preset-input-access preset-input-access-' + d; })
             .call(utilNoAuto)
             .each(function(d) {
@@ -69,7 +68,7 @@ export function uiFieldAccess(field, context) {
 
     function change(d) {
         var tag = {};
-        var value = utilGetSetValue(d3_select(this));
+        var value = context.cleanTagValue(utilGetSetValue(d3_select(this)));
 
         // don't override multiple values with blank string
         if (!value && typeof _tags[d] !== 'string') return;
diff --git a/modules/ui/fields/address.js b/modules/ui/fields/address.js
index 2520a1531..a56bc3449 100644
--- a/modules/ui/fields/address.js
+++ b/modules/ui/fields/address.js
@@ -186,7 +186,6 @@ export function uiFieldAddress(field, context) {
             .append('input')
             .property('type', 'text')
             .call(updatePlaceholder)
-            .attr('maxlength', context.maxCharsForTagValue())
             .attr('class', function (d) { return 'addr-' + d.id; })
             .call(utilNoAuto)
             .each(addDropdown)
@@ -259,10 +258,12 @@ export function uiFieldAddress(field, context) {
                 .each(function (subfield) {
                     var key = field.key + ':' + subfield.id;
 
-                    // don't override multiple values with blank string
-                    if (Array.isArray(_tags[key]) && !this.value) return;
+                    var value = context.cleanTagValue(this.value);
 
-                    tags[key] = this.value || undefined;
+                    // don't override multiple values with blank string
+                    if (Array.isArray(_tags[key]) && !value) return;
+
+                    tags[key] = value || undefined;
                 });
 
             dispatch.call('change', this, tags, onInput);
diff --git a/modules/ui/fields/combo.js b/modules/ui/fields/combo.js
index e0a8d26fe..6ef3c51be 100644
--- a/modules/ui/fields/combo.js
+++ b/modules/ui/fields/combo.js
@@ -290,6 +290,7 @@ export function uiFieldCombo(field, context) {
                         var old = _tags[key];
                         if (typeof old === 'string' && old.toLowerCase() !== 'no') return;
                     }
+                    key = context.cleanTagKey(key);
                     field.keys.push(key);
                     t[key] = 'yes';
                 });
@@ -297,7 +298,7 @@ export function uiFieldCombo(field, context) {
             } else if (isSemi) {
                 var arr = _multiData.map(function(d) { return d.key; });
                 arr = arr.concat(vals);
-                t[field.key] = utilArrayUniq(arr).filter(Boolean).join(';');
+                t[field.key] = context.cleanTagValue(utilArrayUniq(arr).filter(Boolean).join(';'));
             }
 
             window.setTimeout(function() { input.node().focus(); }, 10);
@@ -308,7 +309,7 @@ export function uiFieldCombo(field, context) {
             // don't override multiple values with blank string
             if (!rawValue && Array.isArray(_tags[field.key])) return;
 
-            val = tagValue(rawValue);
+            val = context.cleanTagValue(tagValue(rawValue));
             t[field.key] = val;
         }
 
@@ -383,7 +384,6 @@ export function uiFieldCombo(field, context) {
             .append('input')
             .attr('type', 'text')
             .attr('id', field.domId)
-            .attr('maxlength', context.maxCharsForTagValue())
             .call(utilNoAuto)
             .call(initCombo, selection)
             .merge(input);
@@ -456,8 +456,8 @@ export function uiFieldCombo(field, context) {
                 var commonValues;
                 if (Array.isArray(tags[field.key])) {
 
-                    tags[field.key].forEach(function(tagValue) {
-                        var thisVals = utilArrayUniq((tagValue || '').split(';')).filter(Boolean);
+                    tags[field.key].forEach(function(tagVal) {
+                        var thisVals = utilArrayUniq((tagVal || '').split(';')).filter(Boolean);
                         allValues = allValues.concat(thisVals);
                         if (!commonValues) {
                             commonValues = thisVals;
@@ -544,9 +544,6 @@ export function uiFieldCombo(field, context) {
                 .attr('class', 'remove')
                 .text('×');
 
-            container.selectAll('input[type="text"]')
-                .attr('maxlength', maxLength);
-
         } else {
             var isMixed = Array.isArray(tags[field.key]);
 
diff --git a/modules/ui/fields/cycleway.js b/modules/ui/fields/cycleway.js
index a89035930..acfc37ed5 100644
--- a/modules/ui/fields/cycleway.js
+++ b/modules/ui/fields/cycleway.js
@@ -56,7 +56,6 @@ export function uiFieldCycleway(field, context) {
             .attr('class', 'preset-input-cycleway-wrap')
             .append('input')
             .attr('type', 'text')
-            .attr('maxlength', context.maxCharsForTagValue())
             .attr('class', function(d) { return 'preset-input-cycleway preset-input-' + stripcolon(d); })
             .call(utilNoAuto)
             .each(function(d) {
@@ -77,7 +76,7 @@ export function uiFieldCycleway(field, context) {
 
     function change(key) {
 
-        var newValue = utilGetSetValue(d3_select(this));
+        var newValue = context.cleanTagValue(utilGetSetValue(d3_select(this)));
 
         // don't override multiple values with blank string
         if (!newValue && (Array.isArray(_tags.cycleway) || Array.isArray(_tags[key]))) return;
diff --git a/modules/ui/fields/input.js b/modules/ui/fields/input.js
index 4882402b5..9997b2b65 100644
--- a/modules/ui/fields/input.js
+++ b/modules/ui/fields/input.js
@@ -56,7 +56,6 @@ export function uiFieldText(field, context) {
             .append('input')
             .attr('type', field.type === 'identifier' ? 'text' : field.type)
             .attr('id', field.domId)
-            .attr('maxlength', context.maxCharsForTagValue())
             .classed(field.type, true)
             .call(utilNoAuto)
             .merge(input);
@@ -167,13 +166,13 @@ export function uiFieldText(field, context) {
     function change(onInput) {
         return function() {
             var t = {};
-            var val = utilGetSetValue(input).trim() || undefined;
+            var val = context.cleanTagValue(utilGetSetValue(input));
 
             // don't override multiple values with blank string
             if (!val && Array.isArray(_tags[field.key])) return;
 
             if (!onInput) {
-                if (field.type === 'number' && val !== undefined) {
+                if (field.type === 'number' && val) {
                     var vals = val.split(';');
                     vals = vals.map(function(v) {
                         var num = parseFloat(v.trim(), 10);
@@ -181,9 +180,9 @@ export function uiFieldText(field, context) {
                     });
                     val = vals.join(';');
                 }
-                utilGetSetValue(input, val || '');
+                utilGetSetValue(input, val);
             }
-            t[field.key] = val;
+            t[field.key] = val || undefined;
             dispatch.call('change', this, t, onInput);
         };
     }
diff --git a/modules/ui/fields/localized.js b/modules/ui/fields/localized.js
index 6be23976f..9cd606a18 100644
--- a/modules/ui/fields/localized.js
+++ b/modules/ui/fields/localized.js
@@ -170,7 +170,6 @@ export function uiFieldLocalized(field, context) {
             .attr('type', 'text')
             .attr('id', field.domId)
             .attr('class', 'localized-main')
-            .attr('maxlength', context.maxCharsForTagValue())
             .call(utilNoAuto)
             .merge(input);
 
@@ -385,13 +384,15 @@ export function uiFieldLocalized(field, context) {
                     d3_event.preventDefault();
                     return;
                 }
-                var t = {};
-                var val = utilGetSetValue(d3_select(this)) || undefined;
+
+                var val = context.cleanTagValue(utilGetSetValue(d3_select(this)));
 
                 // don't override multiple values with blank string
                 if (!val && Array.isArray(_tags[field.key])) return;
 
-                t[field.key] = val;
+                var t = {};
+
+                t[field.key] = val || undefined;
                 dispatch.call('change', this, t, onInput);
             };
         }
@@ -420,12 +421,14 @@ export function uiFieldLocalized(field, context) {
             tags[key(d.lang)] = undefined;
         }
 
+        var newKey = lang && context.cleanTagKey(key(lang));
+
         var value = utilGetSetValue(d3_select(this.parentNode).selectAll('.localized-value'));
 
-        if (lang && value) {
-            tags[key(lang)] = value;
-        } else if (lang && _wikiTitles && _wikiTitles[d.lang]) {
-            tags[key(lang)] = _wikiTitles[d.lang];
+        if (newKey && value) {
+            tags[newKey] = value;
+        } else if (newKey && _wikiTitles && _wikiTitles[d.lang]) {
+            tags[newKey] = _wikiTitles[d.lang];
         }
 
         d.lang = lang;
@@ -435,7 +438,7 @@ export function uiFieldLocalized(field, context) {
 
     function changeValue(d) {
         if (!d.lang) return;
-        var value = utilGetSetValue(d3_select(this)) || undefined;
+        var value = context.cleanTagValue(utilGetSetValue(d3_select(this))) || undefined;
 
         // don't override multiple values with blank string
         if (!value && Array.isArray(d.value)) return;
@@ -549,7 +552,6 @@ export function uiFieldLocalized(field, context) {
                 wrap
                     .append('input')
                     .attr('type', 'text')
-                    .attr('maxlength', context.maxCharsForTagValue())
                     .attr('class', 'localized-value')
                     .on('blur', changeValue)
                     .on('change', changeValue);
diff --git a/modules/ui/fields/maxspeed.js b/modules/ui/fields/maxspeed.js
index 0bbee9f10..4e5f230b3 100644
--- a/modules/ui/fields/maxspeed.js
+++ b/modules/ui/fields/maxspeed.js
@@ -43,7 +43,6 @@ export function uiFieldMaxspeed(field, context) {
             .attr('type', 'text')
             .attr('class', 'maxspeed-number')
             .attr('id', field.domId)
-            .attr('maxlength', context.maxCharsForTagValue() - 4)
             .call(utilNoAuto)
             .call(speedCombo)
             .merge(input);
@@ -95,7 +94,7 @@ export function uiFieldMaxspeed(field, context) {
 
     function change() {
         var tag = {};
-        var value = utilGetSetValue(input);
+        var value = utilGetSetValue(input).trim();
 
         // don't override multiple values with blank string
         if (!value && Array.isArray(_tags[field.key])) return;
@@ -103,9 +102,9 @@ export function uiFieldMaxspeed(field, context) {
         if (!value) {
             tag[field.key] = undefined;
         } else if (isNaN(value) || !_isImperial) {
-            tag[field.key] = value;
+            tag[field.key] = context.cleanTagValue(value);
         } else {
-            tag[field.key] = value + ' mph';
+            tag[field.key] = context.cleanTagValue(value + ' mph');
         }
 
         dispatch.call('change', this, tag);
diff --git a/modules/ui/fields/textarea.js b/modules/ui/fields/textarea.js
index 718c62c84..ac5393e7b 100644
--- a/modules/ui/fields/textarea.js
+++ b/modules/ui/fields/textarea.js
@@ -30,7 +30,6 @@ export function uiFieldTextarea(field, context) {
         input = input.enter()
             .append('textarea')
             .attr('id', field.domId)
-            .attr('maxlength', context.maxCharsForTagValue())
             .call(utilNoAuto)
             .on('input', change(true))
             .on('blur', change())
@@ -42,13 +41,13 @@ export function uiFieldTextarea(field, context) {
     function change(onInput) {
         return function() {
 
-            var val = utilGetSetValue(input) || undefined;
+            var val = context.cleanTagValue(utilGetSetValue(input));
 
             // don't override multiple values with blank string
             if (!val && Array.isArray(_tags[field.key])) return;
 
             var t = {};
-            t[field.key] = val;
+            t[field.key] = val || undefined;
             dispatch.call('change', this, t, onInput);
         };
     }
diff --git a/modules/ui/fields/wikidata.js b/modules/ui/fields/wikidata.js
index e27316558..51586b55b 100644
--- a/modules/ui/fields/wikidata.js
+++ b/modules/ui/fields/wikidata.js
@@ -14,8 +14,7 @@ import { svgIcon } from '../../svg/icon';
 import {
     utilGetSetValue,
     utilNoAuto,
-    utilRebind,
-    utilUnicodeCharsTruncated
+    utilRebind
 } from '../../util';
 
 import { t } from '../../core/localizer';
@@ -237,7 +236,7 @@ export function uiFieldWikidata(field, context) {
             }
 
             if (newWikipediaValue) {
-                newWikipediaValue = utilUnicodeCharsTruncated(newWikipediaValue, context.maxCharsForTagValue());
+                newWikipediaValue = context.cleanTagValue(newWikipediaValue);
             }
 
             if (typeof newWikipediaValue === 'undefined') return;
diff --git a/modules/ui/fields/wikipedia.js b/modules/ui/fields/wikipedia.js
index ad62f32a3..3c988b958 100644
--- a/modules/ui/fields/wikipedia.js
+++ b/modules/ui/fields/wikipedia.js
@@ -7,7 +7,7 @@ import { actionChangeTags } from '../../actions/change_tags';
 import { services } from '../../services/index';
 import { svgIcon } from '../../svg/icon';
 import { uiCombobox } from '../combobox';
-import { utilGetSetValue, utilNoAuto, utilRebind, utilUnicodeCharsTruncated } from '../../util';
+import { utilGetSetValue, utilNoAuto, utilRebind } from '../../util';
 
 
 export function uiFieldWikipedia(field, context) {
@@ -115,7 +115,6 @@ export function uiFieldWikipedia(field, context) {
       .attr('type', 'text')
       .attr('class', 'wiki-title')
       .attr('id', field.domId)
-      .attr('maxlength', context.maxCharsForTagValue() - 4)
       .call(utilNoAuto)
       .call(titleCombo)
       .merge(_titleInput);
@@ -192,7 +191,7 @@ export function uiFieldWikipedia(field, context) {
     }
 
     if (value) {
-      syncTags.wikipedia = utilUnicodeCharsTruncated(language()[2] + ':' + value, context.maxCharsForTagValue());
+      syncTags.wikipedia = context.cleanTagValue(language()[2] + ':' + value);
     } else {
       syncTags.wikipedia = undefined;
     }
diff --git a/modules/ui/sections/raw_member_editor.js b/modules/ui/sections/raw_member_editor.js
index ed6e7c478..f99f01438 100644
--- a/modules/ui/sections/raw_member_editor.js
+++ b/modules/ui/sections/raw_member_editor.js
@@ -81,7 +81,7 @@ export function uiSectionRawMemberEditor(context) {
 
     function changeRole(d) {
         var oldRole = d.role;
-        var newRole = d3_select(this).property('value');
+        var newRole = context.cleanRelationRole(d3_select(this).property('value'));
 
         if (oldRole !== newRole) {
             var member = { id: d.id, type: d.type, role: newRole };
@@ -232,7 +232,6 @@ export function uiSectionRawMemberEditor(context) {
                 return d.domId;
             })
             .property('type', 'text')
-            .attr('maxlength', context.maxCharsForRelationRole())
             .attr('placeholder', t('inspector.role'))
             .call(utilNoAuto);
 
diff --git a/modules/ui/sections/raw_membership_editor.js b/modules/ui/sections/raw_membership_editor.js
index d3d1dd974..476603c01 100644
--- a/modules/ui/sections/raw_membership_editor.js
+++ b/modules/ui/sections/raw_membership_editor.js
@@ -67,7 +67,7 @@ export function uiSectionRawMembershipEditor(context) {
         if (_inChange) return;  // avoid accidental recursive call #5731
 
         var oldRole = d.member.role;
-        var newRole = d3_select(this).property('value');
+        var newRole = context.cleanRelationRole(d3_select(this).property('value'));
 
         if (oldRole !== newRole) {
             _inChange = true;
@@ -267,7 +267,6 @@ export function uiSectionRawMembershipEditor(context) {
                 return d.domId;
             })
             .property('type', 'text')
-            .attr('maxlength', context.maxCharsForRelationRole())
             .attr('placeholder', t('inspector.role'))
             .call(utilNoAuto)
             .property('value', function(d) { return d.member.role; })
@@ -315,7 +314,6 @@ export function uiSectionRawMembershipEditor(context) {
             .append('input')
             .attr('class', 'member-role')
             .property('type', 'text')
-            .attr('maxlength', context.maxCharsForRelationRole())
             .attr('placeholder', t('inspector.role'))
             .call(utilNoAuto);
 
@@ -387,7 +385,7 @@ export function uiSectionRawMembershipEditor(context) {
             // remove hover-higlighting
             if (d.relation) utilHighlightEntities([d.relation.id], false, context);
 
-            var role = list.selectAll('.member-row-new .member-role').property('value');
+            var role = context.cleanRelationRole(list.selectAll('.member-row-new .member-role').property('value'));
             addMembership(d, role);
         }
 
diff --git a/modules/ui/sections/raw_tag_editor.js b/modules/ui/sections/raw_tag_editor.js
index 643429f3b..7b25ff41d 100644
--- a/modules/ui/sections/raw_tag_editor.js
+++ b/modules/ui/sections/raw_tag_editor.js
@@ -9,7 +9,7 @@ import { uiTagReference } from '../tag_reference';
 import { prefs } from '../../core/preferences';
 import { t } from '../../core/localizer';
 import { utilArrayDifference, utilArrayIdentical } from '../../util/array';
-import { utilGetSetValue, utilNoAuto, utilRebind, utilTagDiff, utilUnicodeCharsTruncated } from '../../util';
+import { utilGetSetValue, utilNoAuto, utilRebind, utilTagDiff } from '../../util';
 
 export function uiSectionRawTagEditor(id, context) {
 
@@ -187,7 +187,6 @@ export function uiSectionRawTagEditor(id, context) {
             .append('input')
             .property('type', 'text')
             .attr('class', 'key')
-            .attr('maxlength', context.maxCharsForTagKey())
             .call(utilNoAuto)
             .on('blur', keyChange)
             .on('change', keyChange);
@@ -198,7 +197,6 @@ export function uiSectionRawTagEditor(id, context) {
             .append('input')
             .property('type', 'text')
             .attr('class', 'value')
-            .attr('maxlength', context.maxCharsForTagValue())
             .call(utilNoAuto)
             .on('blur', valueChange)
             .on('change', valueChange)
@@ -338,13 +336,11 @@ export function uiSectionRawTagEditor(id, context) {
     function textChanged() {
         var newText = this.value.trim();
         var newTags = {};
-        var maxKeyLength = context.maxCharsForTagKey();
-        var maxValueLength = context.maxCharsForTagValue();
         newText.split('\n').forEach(function(row) {
             var m = row.match(/^\s*([^=]+)=(.*)$/);
             if (m !== null) {
-                var k = utilUnicodeCharsTruncated(unstringify(m[1].trim()), maxKeyLength);
-                var v = utilUnicodeCharsTruncated(unstringify(m[2].trim()), maxValueLength);
+                var k = context.cleanTagKey(unstringify(m[1].trim()));
+                var v = context.cleanTagValue(unstringify(m[2].trim()));
                 newTags[k] = v;
             }
         });
@@ -461,10 +457,11 @@ export function uiSectionRawTagEditor(id, context) {
         if (d3_select(this).attr('readonly')) return;
 
         var kOld = d.key;
-        var kNew = this.value.trim();
-        var row = this.parentNode.parentNode;
-        var inputVal = d3_select(row).selectAll('input.value');
-        var vNew = utilGetSetValue(inputVal);
+
+        // exit if we are currently about to delete this row anyway - #6366
+        if (_pendingChange && _pendingChange.hasOwnProperty(kOld) && _pendingChange[kOld] === undefined) return;
+
+        var kNew = context.cleanTagKey(this.value.trim());
 
         // allow no change if the key should be readonly
         if (isReadOnly({ key: kNew })) {
@@ -472,26 +469,29 @@ export function uiSectionRawTagEditor(id, context) {
             return;
         }
 
-        // switch focus if key is already in use
-        if (kNew && kNew !== kOld) {
-            if (_tags[kNew] !== undefined) {      // new key is already in use
-                this.value = kOld;                // reset the key
-                section.selection().selectAll('.tag-list input.value')
-                    .each(function(d) {
-                        if (d.key === kNew) {     // send focus to that other value combo instead
-                            var input = d3_select(this).node();
-                            input.focus();
-                            input.select();
-                        }
-                    });
-                return;
-            }
+        if (kNew &&
+            kNew !== kOld &&
+            _tags[kNew] !== undefined) {
+            // new key is already in use, switch focus to the existing row
+
+            this.value = kOld;                // reset the key
+            section.selection().selectAll('.tag-list input.value')
+                .each(function(d) {
+                    if (d.key === kNew) {     // send focus to that other value combo instead
+                        var input = d3_select(this).node();
+                        input.focus();
+                        input.select();
+                    }
+                });
+            return;
         }
 
-        _pendingChange  = _pendingChange || {};
 
-        // exit if we are currently about to delete this row anyway - #6366
-        if (_pendingChange.hasOwnProperty(d.key) && _pendingChange[d.key] === undefined) return;
+        var row = this.parentNode.parentNode;
+        var inputVal = d3_select(row).selectAll('input.value');
+        var vNew = context.cleanTagValue(utilGetSetValue(inputVal));
+
+        _pendingChange = _pendingChange || {};
 
         if (kOld) {
             _pendingChange[kOld] = undefined;
@@ -517,12 +517,12 @@ export function uiSectionRawTagEditor(id, context) {
         // exit if this is a multiselection and no value was entered
         if (typeof d.value !== 'string' && !this.value) return;
 
-        _pendingChange  = _pendingChange || {};
-
         // exit if we are currently about to delete this row anyway - #6366
-        if (_pendingChange.hasOwnProperty(d.key) && _pendingChange[d.key] === undefined) return;
+        if (_pendingChange && _pendingChange.hasOwnProperty(d.key) && _pendingChange[d.key] === undefined) return;
 
-        _pendingChange[d.key] = this.value;
+        _pendingChange = _pendingChange || {};
+
+        _pendingChange[d.key] = context.cleanTagValue(this.value);
         scheduleChange();
     }