What is C-3-11?
C-3-11 (교대선원, rotating/relief ship crew) was a temporary sub-category under 단기방문(C-3) issued as a 단수사증 (single-entry visa) to people wanting to enter and exit Korea multiple times within a set number of months (the exact month-count and entry-count figures are blank in the extracted text — a known digit-drop artifact — so they cannot be quoted). The manual explicitly labels it abolished: it was a temporary COVID-19-era guideline that was discontinued once normal visa issuance procedures resumed in June 2022 ('22.6.). It does not appear in the main 세부 약호·구분·대상 table for C-3 (that table lists only C-3-1 through C-3-10); C-3-11 appears only in a separate, later numbered procedures list as item '7. 교대선원 (C-3-11)', directly following item '6. 순수환승 (C-3-10)'. That same numbered list's other items are 1. 단기일반(C-3-1), 2. 단체관광 등(C-3-2), 3. 일반상용(C-3-4), 4. 협정상 일반상용(C-3-5), 5. 일반관광(C-3-9), 6. 순수환승(C-3-10) — confirming the claimant's description of which codes sit alongside it in that list.