Enable CRM 4 URL QueryString Parameter Passing…
It seems worked while CRM 3.0 that one can pass custom variables via URL’s querystring and use it while form’s onload event. but it’s not worked in CRM 4 by default now. to be able to do this, you have to tune the registry.
Create a DWORD registry key named [DisableParameterFilter] under [HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\MSCRM], set the value to 1 , and the do a iisreset, this enable the url querystring parameter passing under CRM 4.
some related discussion here. but still wondering what will be affected by disabling this “ParameterFilter”, since it seems not documented in any documents I’ve seen…