The Scottish Cyclocross Association would like to thank Scottish Cycling for this rule change.
Scottish Cycling's Technical Regulations can be downloaded here. The relevant rules are shown below - you'll also need to enter by the closing date which is two weeks before the race:
12 CYCLO CROSS SPECIFIC REGULATIONS
For SC championships competitors may compete without a licence but will
not be eligible for championship placings. Refer to Tech Reg 18.1.6
Further eligibility requirements must be met:
18.1.2 All SCU Championships shall be open to: -
a) SCU/BCF members (members of clubs affiliated to the SCU)
b) Scottish Nationals (persons born in Scotland)
c) Scottish Residents (persons who have lived in Scotland for three of the
last five years)
d) Persons who have at least one parent who was born in Scotland.
e) Members of the armed forces who meet none of the above, but who by
necessity are required to live in Scotland away from their normal
Persons in sections (b), (c), (d) and (e) must be members of an UCI
recognised Cycling Federation.
18.1.6 Competitors in all Scottish Cycling Championships other than Road Time
Trials and Team Time Trials are required to have a full BC/SC or UCI racing