Go to Tools - VSdocman menu or press VSdocman button on standard toolbar. VSdocman dialog appears, select Project Properties pane. Set Output - File Names page.
Here you can define format of names of generated HTML files.
Numeric file names
File name is converted to a number. It has fixed length so you will not exceed 260 characters limit for paths in Windows. On the other hand, it is not possible to determine which file belongs to which member so you cannot easily create links to them from external files. Moreover, numeric file name is not constant for particular member and may change each time you create new documentation.
Pretty file names
Pretty names are created from member's full name so you can easily create links from external files. The name is constant for particular member and it has the following format:
It starts with frlrf. Then the full name without periods and parameters if any. If method is overloaded, each variant has appended a number to the file name. This number may change so you cannot rely on it. There is still one page without number which lists all overloads and you should point your links to that page.
If the full name is too long or your output folder name is long or very nested, you may exceed 260 characters limit for paths in Windows. In such case you should change your output folder to something short, e,g, c:\out or you should switch to numeric file names.