What is a Help ID
A Help ID is a unique identifier used to display context sensitive help.
In general, all icons in the toolbars have Help IDs, all menu commands, and all controls in dialog boxes. When a user activates Extended Tip Help and points to any of these objects, the application shows the respective help text from the help source files. The link between application and help is the Help ID.
Help IDs are defined by the OOo developers when they write the code. Most often this is an automatic step of their work.
Currently, many Help IDs exist in two types - as a number or a character string. The new UNO Help IDs, used mainly for menu commands, only have strings starting with .uno:
The Application Help uses a file 'helpcontent2/helpers/help_hid.lst' which lists Help IDs. A file like this is used when compiling the Help to generate a binary index file for fast access of the help text (the file used by build may be read from another location). A typical line of this file follows in the example below.
The string SID_ATTRIBUTES_LINE most often is a legacy Help ID no longer in use, if a .uno: ID exists. But don't delete old IDs until you are sure they are not in use...
The number 10143 is used whenever the command (which may be Format - Line or such) is a part of a context menu.
The .uno:FormatLine string is used within menus and in dialog boxes, if applicable.
How to show Help IDs
Define a system environment variable HELP_DEBUG and set it to some value, for example HELP_DEBUG=1
Now the extended tip help shows the Help context and the Help ID below the text.