pattern heading meaning in Information Science terminology / glossary / dictionary is:
The principle incorporated into Library of Congress subject headings in 1974 that allows a full set of free-floating subdivisions to be established for one or a few representatives of a particular category of subject headings or name headings, which are appropriate for use under other main headings belonging to the same category. For example, the subdivision–Biopsy under the pattern heading Heart can be used under the heading Breast even though no specific authority record exists for the combination Breast–Biopsy. The rule does not apply when there is a conflict with a heading established in the subjectauthority file in another form. For example, the subdivision –Dislocation under the pattern heading Foot may not be applied to the heading Joints because the combination Joints–Dislocation is a UF (used for) reference under the heading Dislocations in the subject authority file.