(Latin, "critical preparation"). For a critical edition of a text, footnotes which give possible textual variants for words, phrases, or whole lines. Most texts older than 100 years or so have minor variations throughout; but consider even the following, more recent lines, taken from T.S. Eliot's The Love Song of St. Sebastian:
Until my blood should ring the lamp (7)
And glisten in the light
I should arise your neophyte
And then put out the light
To follow where you lead (11)
The same lines have also been published:
Until my blood should ring the light (7)
And glisten in the light
I should arise, your neophyte
And then put out the light
And follow where you lead (11)
The first version, above, is the most common. "Lamp" in line 7 was corrected from light in the original manuscript by Eliot himself. The comma after "arise" in line 9 is a textual variant of various publications. The initial and in line 11 was a change by Eliot's early editor, Conrad Aiken, and exists in manuscripts in the McKeldin library, whereas Eliot had an original "to".
Problems are compounded the earlier a text was written. Homer, thus, exists in countless editions which have been handed down to us through the centuries. The editor's job is to somehow determine and record which variant is the most ancient or authentic, and note in the apparatus criticus below or following the text what other readings might be possible.
The works of Martial, for example, survives in some 23 manuscripts scattered across Europe. Prefacing the editions is a sigla codicum, or list of manuscripts which assigns each a letter for identification. Thus the line, poem I.10.6, qui iubet ingenium mitius esse feris, is marked:
6 qui iubet Ital.; cui iuuat Aa
As marked in the sigla codicum, Ital. is the consensus of all the Italian manuscripts; Aa is the variant probably stemming from a theoretical archetype of 3 other manuscripts.