Unicode Terms of use (http://www.unicode.org/copyright.html) state that any software that uses their data files (or a modification of it) should carry the Unicode license references.

It seems to me that most Unicode libraries have functions to check if a character is a digit, a letter, a symbol, etc. ans so will contain a modification of the Unicode Data Files (usually in the form of tables).

Does that mean the license applies and all applications that use such Unicode libraries should carry the license?

I've checked around, and it appears very few Unicode software do carry the license, though arguable most of those that didn't carry the license were from companies that were members of the Unicode consortium (do they get license exemption?).

Some (f.i. Mozilla) are only "Liaison Members", and while their software do not carry the license (AFAICT), they do obviously rely on data derived from those data files. Is Mozilla in breach of the license?

Should we carry the license in all apps that include any form of advanced Unicode support? (ie. are bound to rely on the Unicode data files) Or is there some form of broad exemption? (since very very few software out there carries the license)