In DTM, when
_satellite.getVarwas called with a string starting with "param.", the value after the dot was interpreted as a query string argument.
For example on https://www.example.com?foo=cat&bar=dog , calling _satellite.getVar("param.foo") would return "cat". Who knew?
This undocumented feature was not used too often, but we found it here and there then the migration assessement results.