The most common and most likely answer to this crossword clue is the 8 letter word COLOPHON
I've seen this crossword clue in The Guardian
C
O
L
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P
H
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More clues leading to the result COLOPHON
Buddy explains!
The straight part
We know that "mark by which publisher may be recognised" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case mark by which publisher may be recognised = colophon.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does COLOPHON mean?
COLOPHON noun- In manuscripts (typically before the invention of printing), the note, usually at the end, left by the scribe who copied it, giving information on his exemplar, where and when the copy was made, and sometimes, his own name.
- A printer's or publisher's identifying inscription or logo appearing at the front or end of a book, or the same appearing on the spine or dust-jacket. It generally contains factual information about the book, especially about its production, and includes details about typographic style, the fonts used, the paper used, and perhaps the binding method of the book. Also used in a similar fashion for newspapers, magazines, and academic journals.
- A page on a website identifying the details of its creation, such as the author's name and the technologies used.
- A finishing stroke or crowning touch.