Lengthy query string variable missing

I have got quite a lengthy query string variable (value is roughly 600 chars) that I am attempting to achieve from the PHP script. The lengthy the first is not contained in $_REQUEST or $_GET but another variable with shorter value length is. I have shaved off a lot of it to check also it begins going missing once the value reaches 549 chars or even more.

Fortunately the lengthy variable exists in $_SERVER["QUERY_STRING"] so for the time being I am just picking up after that, but was curious regarding if this sounds like a server setting (Apache 2) or something like that with my PHP setup (5.2.17) or script?

BTW, the query string is not something I control so regrettably I can not change how that actually works, for ex. delivering via Publish.

Perhaps you have a hardend/suhosin version of php. It offers configuration directives to limit the size of names and values for input parameters.

suhosin.get.max_title_length

    Type: Integer

    Default: 64

Defines the utmost period of variable names for variables registered with the URL. For array variables this is actually the title while watching indices.

suhosin.get.max_totalname_length

    Type: Integer

    Default: 256

Defines the utmost entire total variable title when registered with the URL. For array variables including all indices.

suhosin.get.max_value_length

    Type: Integer

    Default: 512

Defines the utmost period of a flexible that's registered with the URL.