LINKDATA is an archive format used in Persona 5 Strikers. It was developed by Koei Tecmo Games before RDB. It has most of the game system data, including all text plus some other things.
Cethleann was made by Yretenai and is made to unpack many Koei Tecmo's archive formats.
It is a commandline tool, usage for unpacking P5S PC LINKDATA is:
Cethleann.DataExporter.exe --flayn -g P5SPC (Path to output the extracted files) (Path to the pd_ww folder)
- Do note that LINKDATA consists of 2 files, .BIN (The data) and .IDX (Headers); and IDX file is inside the .exe of the game