This is a bug fix or improvement patch made by Puresabe for Rockman 4, although it seems to work in Megaman USA roms too. It enables you to jump while sliding underwater or near ladders.
Database match: Rockman 4 - Aratanaru Yabou!! (Japan)
Database: No-Intro: Nintendo Entertainment System (v. 20180803-121122)
File SHA-1: C33C6FA5B0A5B010AF6B38CBD22252A595500A5A
File CRC32: 771A9138
ROM SHA-1: 83F5EA60D6E6489EC0E5AF4B938D2D1C8FD24DD5
ROM CRC32: F161A5D8