Preparing DITA Source Documents : Creating Context-Sensitive Help in DITA Source Documents : Understanding Context-Sensitive Help : Understanding Topic ID and File Name Requirements
 
Understanding Topic ID and File Name Requirements
If you are creating context-sensitive help topics using topic IDs, topic IDs must follow these guidelines:
*Must be unique
*Must begin with an alphabetical character
*May contain alphanumeric characters
*May not contain special characters or spaces, with the exception of underscores ( _ )
Dynamic HTML, Eclipse Help, Microsoft HTML Help, Microsoft WinHelp, Oracle Help, Sun, WebWorks Help, and WebWorks Reverb support the use of topic IDs to create context-sensitive help.
If you are creating context-sensitive help topics using file names, file names must follow these guidelines:
*Must be unique
*Must begin with an alphabetical character
*May contain alphanumeric characters
*May not contain special characters or spaces
Simple HTML, and XML+XSL support the use of file names to create context-sensitive help.