How far back can the qualifying connection extend, and what important transmission limitations exist?
Dual citizenship is applicable to a person whose Sri Lankan citizenship has ceased under section 19, 20 or 21 of the Citizenship Act, No 18 of 1948, or is likely to cease; it extends to the spouse or an unmarried child under the age of 22 years of such an applicant (Category 1.G), with child applications submitted before completing 21 years and 06 months, and eligible spouses or children are limited to persons whose Sri Lankan citizenship has ceased under section 19, 20 or 21 or is likely to cease.
See recorded sources
Limits of the record- Rules describe eligibility for dual citizenship, on which the visa exemption rests, not the exemption itself.