Where by a date is not really recognised particularly, "c. " might be useful for "circa". Other illustrations are offered at WP:APPROXDATE, although "fl. " for "floruit" must be averted as It's not necessarily universally understood. Centuries should not be abbreviated "c. " a result of the likely for confusion https://stephenswzvu.hamachiwiki.com/1525752/5_simple_techniques_for_youtube