Cr5
From Market Ruler Help
cr5 is the Query String variable configured to capture an additional landing dimension for an advertising campaign.
cr5 is the indexed query strings and allows for up to 8 different landing dimensions to be recorded using query strings which are indexed from 0 to 7.
Synonyms can be also used:
When it appears in a URL:
https://www.example.com?cr5=College+Educated
When it appears in a URL:
https://www.example.com?cr5=no-sample