Use "and" instead of &, unless part of a proper noun or a common abbreviation. For example: Notices and slips, not Notices & slips; Baker & Taylor, R&D.
item
Base terminology
Use "item", not "document".
item type
Base terminology
(Koha item type) Use "item type" for interface elements and when referring to Koha item types, for example, in form labels, table column headings, hints, and text. Do not use "itemtype" unless directly referencing the database "itemtype" field name, the same as you would do with any other database table or field name.
OPAC
Base terminology
Use "OPAC", not "Opac" or "opac" when abbreviating online public access catalog(ue), including in system preference names.
show
Base terminology
Use "show/don't show" in system preference options, not "display/don't display".
staff client
Base terminology
Do not use. Use "staff interface", not "staff client", "staff intranet", or "intranet".