According to these:

Writing .info files (Drupal 7.x)
#1346158: Decide on coding standard for capitalization of module names [policy, no patch]

Proper Case should be used. So, "Field Collection" instead of "Field collection".

Comments

jmuzz’s picture

Issue summary: View changes

I agree but it's more than just the info file that will need to be changed. Everywhere in the module it should be "Field Collection" when referring to the module name and "Field collection / field collection" when referring to a field, but only if it's written like a noun. So for example "This is a Field Collection field" meaning a field from the Field Collection module and "This is a field collection."