This paper presents the identification in corpora of relational adjectives in French, phenomena considered by linguists as highly informative. The approach uses a termer which is applied to a tagged and lemmatized corpus. Relational adjectives and compound nouns which include a relational adjective are then quantified and their informative status is evaluated thanks to a thesaurus of the domain. The author concludes with a discussion of the interesting status of such adjectives and compound nouns for terminology extraction and other automatic terminology tasks.