That sub looks like part of a module or class. Can't really answer your question because that sub depends on some other information. The INISection variable for example appears to be a module-level or public variable that is populated elsewhere.

I also think that the code may be used for a custom INI file. I say that because the code is looking for Chr$(0) as a delimiter where [ ] symbols would be expected. But of course those could have been replaced with Chr$(0) elsewhere in the original code. Otherwise, you'd have to know the structure of the custom INI to guarantee you understand the routine. And if using APIs to read/write INIs, you don't need manual parsing routines.