MAME 0.235 was released in June 2021. ROMs are "frozen" to the logic of that specific release. 2. Understand ROM Set Types
MAME 0.235, released in August 2021, remains a popular "snapshot" version for arcade enthusiasts because of its stability and the significant expansion of the emulated library it introduced. Core Review: MAME 0.235 ROM Set Breadth of Library : This version is notable for its extensive support of mame 0.235 roms
If you are looking for these specific ROMs today, they are often archived as Non-merged Merged Sets MAME 0