Dear Sirs, Mesdames, Unspecified Neuters, and others:
The heading to the page http://agnes.dida.physik.uni-essen.de/~gnu-pascal/gpc_4.html#SEC4 3.1 General Changes And Possible Incompatibilies To Previous Versions
and the link to it on the page http://agnes.dida.physik.uni-essen.de/~gnu-pascal/news.html
(there may be other links - I haven't searched) is not in English (not even International English).
It should read
"Incompatibilies To" <- "Incompatibilities With"
Normally, the preposition "With", articles and conjunctions shouldn't be capitalised either, except at the start of a sentence. The site is notably inconsistent in its capitalisation style, so I feel free to suggest a merely local change.
I propose a squeakily-clean replacement with
3.1 General Changes and Possible Incompatibilities with Previous Versions
You could also port the documentation to early modern English printing style and write
3.1 General Changes And possible Incompatibilities with previous Versions, but I won't undertake this task myself.
Good luck!
Bernard Leak.