The Ontologies of Linguistic Annotations, shortly OLiA, are multilingual ontologies of various linguistic data categories.

OLiA was originally developed in the context of the collaborative project "Sustainability of Linguistic Resources" between three German Collaborative Research Centres (SFBs): SFB 441 (University Tübingen), SFB 538 (University Hamburg) and SFB 632 (University Potsdam/Berlin).

OLiA represents, in forms of annotation schemes, different morphological, morphosyntactic and syntactic phenomena, such as inflectional morphology, word classes, phrase and edge labels of different syntax annotations, etc. Furthermore, it provides a tag set for annotating typical discourse phenomena, such as co-reference, discourse relations, discourse structure and information structure.

OLiA provides:

• an ontology of reference terms (OLiA Reference Model) that specifies classes for linguistic categories, and grammatical features and properties defining relations between them;

• ontological models of annotation schemes (Multiple OLiA Annotation Models). There are 34 annotation models for about 69 different languages or language stages;

• for every Annotation Model, a Linking Model, that specifies the relationships between the concepts in ontological models of annotation schemes (Annotation Models) and the generalized vocabulary for discourse annotation (Reference Model)