[Heb-NACO] "Nidpas me-ḥadash be-tosefet...": 245/250/500?

[Jasmin Nof]

When is such a statement as the above, in my case "nidpas me-ḥadash 
be-tosefet merubah ʻal ha-rishonim, mugahim mi-kol ha-ṭaʻuyot she-naflu 
ba-defusim ha-ḳodmim...", placed in the 245$b, when in the 250, and when 
in the 500?  Or in some cases, split between the 250 Nidpas me-ḥadash 
and 500 Be-tosefet ...?   I've seen various practices and don't know 
what the determining factor is; or is there not one -- aka, "cataloger's 
judgement"?

Thanks, Jasmin

-- 
Jasmin Nof
Hebraica Cataloging Librarian
University of Pennsylvania
Van Pelt-Dietrich Library Center
3420 Walnut Street
Philadelphia, PA 19104-6206
T. 215-746-6397
F. 215-573-9610
jnof at upenn.edu