server-side x is an adjective and a noun.
Introduction to the Server Side [used as noun, no dash, unusual but OK
**Welcome to the MDN beginner's server-side programming course! **
Perhaps the most significant benefit of server-side code is that
it allows you to tailor website content for individual users.
If you are just talking, and know what is being referred to, you can use server side with no noun or dash. If, however, a noun is used, it's best to use a dash.
server-side management and client-side management, follow the same rule.
These things are much clearer when a dash is used.
Server-side vs. client-only rules Outlook for Microsoft 365 Outlook 2019 Outlook 2016 Outlook 2013 Rules are either server-side or
client-only based on the conditions and actions you apply to them.
Server-side rules use conditions and actions handled by the Exchange
server, and these rules run whether or not you log in to Outlook on
your computer. Here’s an example of a server-side rule:
server-side versus client-only rules
Summary: server-side x, client-side x are used as adjectives plus a noun.
In the Microsoft example, you can even see: client-only rules. Also, an adjective plus a noun. There are others but I don't have them all in my head.
This is exactly like: sugar-free drinks.
When you don't see a dash, it's because people do not know or are lazy.