On December 20th, the founder of CBRC-20 deployed SYMM on both BRC-20 and CBRC-20's inscription 48315131 simultaneously. Due to the non-stackable properties of the BRC-20 and CBRC-20 meta-protocols, all deployment, minting, and transfer operations of both meta-protocols can be engraved in one inscription.
To hold the "rare" SYMM token, you must engrave both BRC20's SYMM and CBRC20's SYMM on the same minting/transfer, which is called the OSMOSIS experiment and is a meta-meta protocol.
SYMM is the first experiment of its kind, and the founder of CBRC-20 believes it is an interesting experiment, but does not promise that SYMM has any value.