Why would you need a calibredrc license if you're just running Calibre LVS?
Calibre LVS requires a Calibre DRC (calibredrc) license when running Electrical Rule Checks (ERC).
The specification statements that will trigger ERC within Calibre LVS are:
ERC Select Check
LVS Execute ERC
ERC can be thought of a DRC-type checks performed as a part of LVS. ERC is a separte task performed as part of circuit extraction during an LVS run which means a separate results database and a dedicated set of specification statements to control operations and results generation. Many of the ERC statements are similar to their respective DRC specification statements.
Typical ERC operations include PATHCHK to check for gates that are not connected either to power or ground, and finding nets without labels.
Details concerning ERC and the specification statements associated with the ERC functionality can be found in the SVRF Manual as well as the Calibre Verification User's Manual.
Details concerning the required licenses, considerations, and exceptions are covered in the Calibre Administrators Guide.