HTTP URL - allowed characters in parameter names

http url character-encoding specifications
Tomalak picture Tomalak · May 2, 2009 · Viewed 23.7k times · Source

Is there any formal restriction as to which characters are allowed in URL parameter names?

I've been reading RFC3986 ("Uniform Resource Identifier (URI): Generic Syntax") but came to no definitive conclusion.

I know there are practical limitations, but would it actually be forbidden to do something like:

param with\funny<chars>=some_value

as long as I escape it correctly:

param%20with%1cfunny%3cchars%3e=some_value

Answer

Konrad Rudolph picture Konrad Rudolph · May 2, 2009

There are no restrictions on escaped parameter names in the URI specs. There might be restrictions in the server-side software that you use, though. This is especially true if you use “homemade” scripts to interpret URIs.

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