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.

nœud de la tête ‘ascending node’

Arabic

References: PH Morelon: I.15, 58
Translation of:
Arabic: عقدة الرأس  [PH Morelon: I.15, 59:17-18]
Synonyms:
عقدة الرأس [PH Morelon: I.15, 59:17-18]