Under Mexican regulations, repurchase transactions (Repos) "are those by which the purchaser acquires, for a sum of money, the ownership of debt securities and undertakes to transfer to the purchaser the ownership of as many securities of the same kind within the agreed term and against the reimbursement of the same price, plus a premium..."
Source:
https://www.banxico.org.mx/elib/mercado-valores-gub/OEBPS/Text/iv.html