Where to publish a long classification? Suppose that the classification of some mathematical (say algebraic) notions requires (say) 70 pages. Let clarify that (say) 90% of the pages are used to write the result itself, whereas only 10% are required to introduce the notions, to mention some theorems and to explain the computer programs used. Finally, assume that the data of this classification is useful to some (pure) mathematicians, and also to some physicists (like an atlas).
Question: Where to published such a classification? (refereed) book or journal? Where?
The classification I have in mind: multiplicity-free complex fusion categories up to rank $6$, and braiding structures.
 A: Perhaps I can try a suggestion: a journal which accepts long papers on the topics you sketched, aimed towards pure and applied mathematicians (including physicists and engineers), which has also an illustrious history is the Journal published by Castelnuovo Institute of Mathematics of the Sapienza University of Rome, i. e. the "Rendiconti di Matematica e delle sue Applicazioni". On the homepage of the Journal, you can read the following statements:

The Journal "Rendiconti di Matematica e delle sue Applicazioni" is regularly issued since 1914.
The Journal traditionally publishes high-quality research articles in Pure and Applied Mathematics and adheres to the EMS Code of Practice.


Articles of any length are considered for publication. Submission of surveys, of articles of foundational nature, of doctoral dissertations etc. is also encouraged.
Every article submitted is subjected to a first screening by the Editorial board: if the manuscript meets the journal’s basic requirements, it will be sent to a referee for a single blind peer review process. Once a paper is accepted it goes immediately into production and published online shortly after the approval of galley proofs.

I am almost sure that the impact factor of the journal is not "between the top ones": however in the past it has published several important papers and many illustrious mathematicians have been its directors (Volterra, Severi, Segre, Fichera, to cite a few names). Well, my two cents.
