PII Entity Recognition: `Password` category never detected

Hello, I’m using Azure AI Services – Language PII Entity Recognition via REST, but the Password category is never detected, even when explicitly included in piiCategories.

• Azure Region: Japan East
• Service: Azure AI services
• API: 2025-11-15-preview
• Client: REST
• API: Analyze Text
• Path: /language/:analyze-text
• api-version: 2025-11-15-preview
• kind: PiiEntityRecognition

Person / URL detected depending on input. Password is never returned in the entities list.

payload

{
  "kind": "PiiEntityRecognition",
  "parameters": {
	"modelVersion": "2025-11-15-preview",
    "piiCategories": ["Password", "Person", "URL"],
	},
	"analysisInput": {     
		"documents": [  
		     { 
		        "id": "1", 
		        "language": "en",
		        "text": "Dummy text for testing. My name is 
			}
    ]
  }
}

result

{'kind': 'PiiEntityRecognitionResults', 'results': {'statistics': {'documentsCount': 1, 'validDocumentsCount': 1, 'erroneousDocumentsCount': 0, 'transactionsCount': 1}, 'documents': [{'redactedText': 'Dummy text for testing. My name is ****. Password is test_password_1234. Link: *******************', 'id': '1', 'statistics': {'charactersCount': 98, 'transactionsCount': 1}, 'entities': [{'text': 'john', 'category': 'Person', 'type': 'Person', 'offset': 35, 'length': 4, 'mask': '****', 'maskOffset': 35, 'maskLength': 4, 'confidenceScore': 1.0, 'tags': [{'name': 'Person', 'confidenceScore': 1.0}]}, {'text': 'https://example.com', 'category': 'URL', 'type': 'URL', 'offset': 79, 'length': 19, 'mask': '*******************', 'maskOffset': 79, 'maskLength': 19, 'confidenceScore': 0.8, 'tags': [{'name': 'URL', 'confidenceScore': 0.8}]}], 'warnings': []}], 'errors': [], 'modelVersion': '2025-11-15-preview'}}

1. Is Password expected to detect generic “password is …” patterns in text, or is it limited to specific Azure-related formats (e.g., AzurePublishSettingPassword)?
2. Are there any known limitations (Preview behavior, English Only, region/model availability) that would explain why Password is never detected?
3. Is my usage of POST /language/:analyze-text with api-version=2025-11-15-preview correct for Password detection?