diff --git a/src/frontend/utils/PLC/xml-generator/codesys/base-xml.ts b/src/frontend/utils/PLC/xml-generator/codesys/base-xml.ts
index 1d6618612..8696a46bc 100644
--- a/src/frontend/utils/PLC/xml-generator/codesys/base-xml.ts
+++ b/src/frontend/utils/PLC/xml-generator/codesys/base-xml.ts
@@ -5,6 +5,7 @@ import { formatDate } from '../../../format-date'
 const getBaseCodeSysXmlStructure = (): BaseXml => ({
   project: {
     '@xmlns': 'http://www.plcopen.org/xml/tc6_0200',
+    '@xmlns:xhtml': 'http://www.w3.org/1999/xhtml',
     fileHeader: {
       '@companyName': 'Unknown',
       '@productName': 'Unnamed',
diff --git a/src/frontend/utils/PLC/xml-generator/xml-generator-initial-values.spec.ts b/src/frontend/utils/PLC/xml-generator/xml-generator-initial-values.spec.ts
new file mode 100644
index 000000000..5e72b22c0
--- /dev/null
+++ b/src/frontend/utils/PLC/xml-generator/xml-generator-initial-values.spec.ts
@@ -0,0 +1,137 @@
+import type { PLCConfiguration, PLCPou } from '@root/middleware/shared/ports/open-plc-types'
+
+import { codeSysInstanceToXml } from './codesys/instances-xml'
+import { getBaseCodeSysXmlStructure } from './codesys/base-xml'
+import { codeSysParseInterface } from './codesys/pou-xml'
+import { getBaseOldEditorXmlStructure } from './old-editor/base-xml'
+import { oldEditorInstanceToXml } from './old-editor/instances-xml'
+import { oldEditorParseInterface } from './old-editor/pou-xml'
+
+type RuntimeVariableInitialValue = boolean | number | string | null
+
+type TestPou = Omit<PLCPou, 'data'> & {
+  data: Omit<PLCPou['data'], 'variables'> & {
+    variables: Array<Omit<PLCPou['data']['variables'][number], 'initialValue'> & { initialValue: RuntimeVariableInitialValue }>
+  }
+}
+
+type TestConfiguration = Omit<PLCConfiguration, 'resource'> & {
+  resource: Omit<PLCConfiguration['resource'], 'globalVariables'> & {
+    globalVariables: Array<
+      Omit<PLCConfiguration['resource']['globalVariables'][number], 'initialValue'> & {
+        initialValue: RuntimeVariableInitialValue
+      }
+    >
+  }
+}
+
+describe('XML generator initial values', () => {
+  const buildPou = (initialValue: boolean | number): PLCPou => {
+    const pou = {
+      type: 'program',
+      data: {
+        name: 'Main',
+        language: 'st',
+        variables: [
+          {
+            name: 'flag',
+            class: 'local',
+            type: { definition: 'base-type', value: 'bool' },
+            location: '%QX0.0',
+            initialValue,
+            documentation: '',
+          },
+        ],
+        body: { language: 'st', value: '' },
+        documentation: '',
+      },
+    } satisfies TestPou
+
+    return pou as unknown as PLCPou
+  }
+
+  const buildConfiguration = (initialValue: boolean | number): PLCConfiguration => {
+    const configuration = {
+      resource: {
+        tasks: [],
+        instances: [],
+        globalVariables: [
+          {
+            name: 'globalFlag',
+            location: '%QX0.0',
+            type: { definition: 'base-type', value: 'bool' },
+            initialValue,
+            documentation: '',
+          },
+        ],
+      },
+    } satisfies TestConfiguration
+
+    return configuration as unknown as PLCConfiguration
+  }
+
+  const buildCodeSysXml = () => getBaseCodeSysXmlStructure()
+
+  const buildOldEditorXml = () => getBaseOldEditorXmlStructure()
+
+  it.each([
+    ['codesys interface', codeSysParseInterface],
+    ['old editor interface', oldEditorParseInterface],
+  ])('keeps false BOOL initial values for %s', (_label, parseInterface) => {
+    const xml = parseInterface(buildPou(false))
+    expect(xml.localVars?.variable?.[0]?.initialValue).toEqual({
+      simpleValue: {
+        '@value': 'false',
+      },
+    })
+  })
+
+  it('keeps numeric zero initial values for codesys globals', () => {
+    const xml = codeSysInstanceToXml(buildCodeSysXml(), buildConfiguration(0))
+    expect(xml.project.instances.configurations.configuration.globalVars?.variable?.[0]?.initialValue).toEqual({
+      simpleValue: {
+        '@value': '0',
+      },
+    })
+  })
+
+  it('keeps numeric zero initial values for old editor globals', () => {
+    const xml = oldEditorInstanceToXml(buildOldEditorXml(), buildConfiguration(0))
+    expect(xml.project.instances.configurations.configuration.globalVars?.variable?.[0]?.initialValue).toEqual({
+      simpleValue: {
+        '@value': '0',
+      },
+    })
+  })
+
+  it('declares the xhtml namespace in codesys exports when variable documentation is present', () => {
+    const xml = getBaseCodeSysXmlStructure()
+    const pouWithDocumentation = {
+      type: 'program',
+      data: {
+        name: 'Main',
+        language: 'st',
+        variables: [
+          {
+            name: 'flag',
+            class: 'local',
+            type: { definition: 'base-type', value: 'bool' },
+            location: '',
+            initialValue: '',
+            documentation: 'commento reset',
+          },
+        ],
+        body: { language: 'st', value: '' },
+        documentation: '',
+      },
+    } satisfies PLCPou
+    const withDocumentation = codeSysParseInterface(pouWithDocumentation)
+
+    expect(xml.project['@xmlns:xhtml']).toBe('http://www.w3.org/1999/xhtml')
+    expect(withDocumentation.localVars?.variable?.[0]?.documentation).toEqual({
+      'xhtml:p': {
+        $: 'commento reset',
+      },
+    })
+  })
+})
diff --git a/src/middleware/shared/ports/xml-types/codesys/base-diagram.ts b/src/middleware/shared/ports/xml-types/codesys/base-diagram.ts
index ccaf489a0..763c3065b 100644
--- a/src/middleware/shared/ports/xml-types/codesys/base-diagram.ts
+++ b/src/middleware/shared/ports/xml-types/codesys/base-diagram.ts
@@ -9,6 +9,7 @@ import { variableXMLSchema } from './variable/variable-diagram'
 const baseXmlSchema = z.object({
   project: z.object({
     '@xmlns': z.string().default('http://www.plcopen.org/xml/tc6_0200'),
+    '@xmlns:xhtml': z.string().default('http://www.w3.org/1999/xhtml'),
 
     fileHeader: z.object({
       '@companyName': z.string().default('Unknown'),