Whether a font may go into a client's work at all is a question of its licence, and an OpenType font carries the answer in its name table. The License section lists the licences the fonts of the collection are under, the commonest first, and filters on the one picked.
The fields are free text that every foundry words its own way, so Fontmatrix recognises the well-known licences — the SIL Open Font License, Apache, the GNU licences, MIT, BSD, the Creative Commons family, the Ubuntu font licence — by the sentences and addresses they are stated with. A font whose licence is none of them is listed as Another licence, one that reserves everything and grants nothing as All rights reserved, and one that says nothing at all as No licence information. The name of the licence is also shown on the Info page, above the text the font itself gives.
A licence recognised from free text is a guide, not a legal opinion: read the text on the Info page before relying on it.