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.

الخطّ الذي يوتر الزاوية القائمة ‘hypotenuse’

Arabic

References: Plan. Sidoli+Berggren: 211(e), 223, 255, 325, 356(e), 375
Modern translations:
English: hypotenuse [Plan. Sidoli+Berggren: ?]