SGI IRIX licenses?

[Richard]

I've not installed IRIX from scratch before.  I recently purchased
some install media from ebay and the item description said "does not
include licenses".  Is this boiler plate disclaimer, or am I still
needing something else to install the OS?  Another item on ebay says
it *does* include licenses.  Is there some sort of license key?
Does SGI have a hobbyist/deprecated-ware license available?
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