I've been trying to find out this for AGES, with no luck. It's probably easy to find out...If I only KNEW THE NAME OF IT.

You know those marks above letters than are supposed to modify their pronunciation. For example, the downward stroke on, 'cafe', or the V-shaped thing in words such as 'melee.' Or the two dots on top of a U that extend its sound. What is the COLLECTIVE TERM FOR THESE MARKS? Also, is there a detailed guide which tells you what mark makes what sound.etc? Thanks for your help.
Hiya Anon

I think 'diacritic' is the word you're desperately seeking for... I also believe 'diacritical mak' would be more often used than 'diacritic' to refer to those weird little signs added on top or below latin alphabet letters in order to modify their pronunciation.

Hope this helps...
Waïti (I'm a diacritical alias myself, by the way...)
I agree. I call those marks diacritics.