If your processing depends on all hypertext links being lowercase, you can include the following setting:
[HTMLOptions] ; MakeFileHrefsLower = No (default, leave case unchanged) or Yes (old) MakeFileHrefsLower = Yes
This setting applies to hypertext links and interfile cross references. When you use the FileName property to name the section that contains the cross-reference destination, the setting applies also to cross references within the same file (see §43.2.3.3 Creating special paragraph formats to name output files).