The following is an extract of UK Athletics Rules for Competition:
RULE 9 COUNTY, DISTRICT AND REGIONAL QUALIFICATIONS
1. English County Qualification
(1) County Championships are open to all eligible athletes possessing a
County qualification.
(2) A County qualification may be acquired as follows:
(a) By birth
(b) By nine month’s continuous bona fide residence in the County
immediately prior to the competition.
(c) By service in a Unit of HM Forces stationed in the County for nine
months immediately prior to the date of the competition. Temporary
absence on duty shall not break a qualification acquired under this
paragraph
NOTE 2: Membership of a Club affiliated to a County Association does not, of
itself, provide an athlete with a County qualification unless at least one of (a) –
(c) above is satisfied.
(3) Competitors who have qualified and competed, under (2) b or (2) c above
retain that qualification until they have acquired a residential qualification and
competed in the Championship of another County, or represented another
County in an Inter-County Championship.
(4) A student at school, college or university does not acquire a residential
qualification by residential qualification by residence in the County during term
time only
(5) An athlete who has competed in a County Championship
or represented a County in an Inter-County
competition, may not compete in the Championships of, nor represent, another
County in that Competition Year.
For the avoidance of doubt on 24/06/13 the Notts AAA Road Running Sub-Committee passed the following motion:
In all Nottinghamshire Road Running County Championships athletes must wear the vest of their first claim affiliated club, their County or National vest or any other representative vest approved by the UKA.
This rule does not apply to unaffiliated runners.
For the avoidance of doubt on 04/09/13 the Notts AAA Road Running Sub-Committee passed the following motion:
No entries on the day shall be allowed in any Nottinghamshire Road Running County Championships.
On 17/09/18 the Notts AAA main committee approved a proposal that for the U17 and U20 categories in the 5k County Championships the relevant date would be the age of the runner on race day.