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.

observation ‘observation’

English

References: Alm. Toomer: 38; 38; 43. – PH Hamm: I.2:1, 45:17. – PH Morelon: I.2:1, 16:16
Translation of:
Greek: τήρησις [Alm. Heiberg: I.2, 9:15; I.6, 20:11]
Greek: παρατήρησις [Alm. Heiberg: I.3, 10:5. – PH Heiberg: I.2:1, 72:9]
Arabic: رَصْد [PH Morelon: I.2:1, 17:9]