What is license feature "Virtuoso_Spectre_GXL_MMSIM_Lk", and how to use it?

Hi there! Checking the license usage at my site (lmstat output) I find situations like the following for the spectre licenses:

Virtuoso_Multi_mode_Simulation      licenses: 180    used: 159    free: 21
Virtuoso_Spectre_GXL_MMSIM_Lk    licenses: 180    used: 11    free: 169

Al my simulations seem to check out only the "Virtuoso_Multi_mode_Simulation" feature, so I am wondering, what are all those "Virtuoso_Spectre_GXL_MMSIM_Lk" unused licenses? Is there a way I can tell ADE/ADE-XL to use those instead of "Virtuoso_Multi_mode_Simulation"? Often I have a hard time finding enough licenses (a couple of corners for and ADC (using APS) seem to easily check out several tenths of licenses!), so using these instead would be a big help!

Thanks and regards,

Jorge.