
The post-processors for tt(groff) output are quite complex. Similar to the 
HTML postprocessor, labels and references need to be fixed and a table of 
contents must be created. Furthermore, tt(groff) and its macros require an 
unusually strict and unreadable input (well, in my opinion they do). The 
complexity of the tt(groff) conversions lies therefore in the post-processor.

The labels and references are resolved via a post-processor which is 
similar to the HTML postprocessor: the tt(.yodltagstart.) and 
tt(.yodltagend.) strings, though in uppercase, are reserved. The 
converters also introduce an extra internal label for usage in the
table of contents generation: tt(.yoldtoccommand.).

An in-depth description of the post-processor would be beyond this document. 
The post-processor is a bf(C) program tt(yodlfixlabels).
