According to the search results, folio charges in South Indian Bank are charges that are levied on current, cash credit, and overdraft accounts in CBS branches. These charges are Rs. 20/- per folio, and for accounts maintained on computers, 40 entries or part thereof are treated as one ledger folio. The compendium of service charges also mentions folio charges, which vary based on the amount maintained in the account. For example, for accounts with an average balance of up to Rs. 1.00 lakh, folio charges are Rs. 20/- per folio. CD SMART, a type of account offered by South Indian Bank, does not have any folio charges.