BIS is the international standard that defines "SI" units for BIM parameters.
Each parameter starts with a hashtag to identify that it is a BIS unit.
The units are interoperable between platforms.
BIS+ is the global coding standard developed for BIM products for international standardisation. The language is a simplified coding platform specifically for BIM and allows bi-directional interoperability with other coding platforms.
Some typical examples from the BIS standard are given below:
#FLW - Flow rate (water)
#LG - Length
#WI - Width
The standard was developed by Autodesk following an idea posted on one of its message boards.
Wikipedia entry 11.06.2024