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.

ظاهر‘appearance’

Arabic

References: PH Morelon: I.1:2, 15:6; I.1:4, 17:2
Translation of:
Greek: φαινόμενον [PH Heiberg: I.1:2, 70:6; I.1:4, 70:20-21]
Modern translations:
French: apparence [PH Morelon: I.1:2, 14:11; I.1:4, 16:4]