[fpc-pascal] Migrating from FPC 2.6.4 to 3.0.0 . What should I be aware?

[Krzysztof]

Hi,

I'm planning constantly moving my apps to FPC 3.0.0. Compiled the
smallest app and everything seems to working fine. In official recent
changes list I read that main different is in unicode / utf8 /
codepage. What does it mean? Is there any simple real example with
"what you did in FPC 2.6.4 and can't do in 3.0.0"? Does it mean that
String type has in FPC 3.0.0 different behavior?

Regards