There are some cases where it's stated that the word should start with an uppercase letter. I changed what was possible, but sometimes there is no way to write something lowercase in german. I mean, it's possible, but it also is wrong. German depends way more on uppercase-lowercase-letters than english.
For exapmle the word "pilot", what means "Pilot" in german. No matter where "Pilot" is in a sentence, it's always written with uppercase "P". It's part of the base concept of written german.
So, is it really a SHOULD, or is it a MUST?