An external division of the edition in which all apparatus criticus features and notes are explicitly tagged.
The simplest entry in an epigraphic or papyrological apparatus criticus is a general comment on the text as a whole, with no specific line reference or textual feature described. (Like all external apparatus features described in this page, this example should appear in the <div type="apparatus">, and perhaps be grouped together in a <listApp>.)
The second example is of a simple comment, but tied to a particular line or text fragment (using in this case the attribute loc, which contains a human-readable or "canonical" citation for the line referenced):
Alternative restorations, perhaps recording the opinion of previous editors or attributing current readings to them, may also be tagged explicitly in the external apparatus division:
An <app> element in the external apparatus may also point directly to a feature tagged within the text transcription division, in order to comment upon it, or simply to display the marked-up feature without duplicating the markup. (Similar to the practice of inline apparatus discussed elsewhere.)
Variant readings may also arise not from a disagreement among editors, but from genuine ambiguity in reading. An unclear letter with several possible interpretations might appear in the apparatus (or in the text itself) as: