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.

زاوية قائمة‘right angle’

Arabic

References: PH Morelon: I.3:4, 19:12
Translation of:
Greek: ὀρθὴ (γωνία) [PH Heiberg: I.3:4, 74:15]
Modern translations:
French: angle droit [PH Morelon: I.3:4, 18:16]
German: rechte Winkel [PH Nix: I.3:4, 75:21-22]