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.

طبيعة ‘nature’

Arabic

References: PH Morelon: I.2:5, 19:2
Translation of:
Greek: φύσις [PH Heiberg: I.2:5, 74:2]
Modern translations:
French: nature [PH Morelon: I.2:5, 18:3]
German: Natur [PH Nix: I.2:5, 75:2]