Subject This relation links a Descriptor with another Descriptor within a certain time interval, for instance when a Term is frequently used for describing News central event developping on several days DL This relation gives the possibility to create post-coordonated Descriptors by using (i.e. by combining) the existing Descriptors AT This relation links a Descriptor with a Descriptor from another Axis, and is not symmetric, so that the “central” thesaurus remains “clean” from any incoming link. LT