What does "may" mean when used as a verb in a text of law in the US?
For example, if the law say "X may do Y", is it guaranteed that X can do Y, or does that mean that perhaps the judge or whoever has the decision power will grant the X the right to do Y, but not this isn't sure at all?
Actual example from 8 C.F.R. 316.5(c)(1)(i) (see emphasis):
(c) Disruption of continuity of residence -
(1) Absence from the United States -
(i) For continuous periods of between six (6) months and one (1) year. Absences from the United States for continuous periods of between six (6) months and one (1) year during the periods for which continuous residence is required under § 316.2 (a)(3) and (a)(6) shall disrupt the continuity of such residence for purposes of this part unless the applicant can establish otherwise to the satisfaction of the Service. This finding remains valid even if the applicant did not apply for or otherwise request a nonresident classification for tax purposes, did not document an abandonment of lawful permanent resident status, and is still considered a lawful permanent resident under immigration laws. The types of documentation which may establish that the applicant did not disrupt the continuity of his or her residence in the United States during an extended absence include, but are not limited to, evidence that during the absence:
(A) The applicant did not terminate his or her employment in the United States;
(B) The applicant's immediate family remained in the United States;
(C) The applicant retained full access to his or her United States abode; or
(D) The applicant did not obtain employment while abroad.
In this example, if one satisfies A, B, C, or D, is one guaranteed not to disrupt the continuity of my residence for the purpose of naturalization?