PAL

Ptolemaeus Arabus et Latinus

_ (the underscore) is the placeholder for exactly one character.
% (the percent sign) is the placeholder for no, one or more than one character.
%% (two percent signs) is the placeholder for no, one or more than one character, but not for blank space (so that a search ends at word boundaries).

At the beginning and at the end, these placeholders are superfluous.

circulaire‘circular’

French

References: PH Morelon: I.1:2, 14:12; I.1:5, 16:9
Translation of:
Arabic: مستدير [PH Morelon: I.1:2, 15:7; I.1:5, 17:6]