> For the complete documentation index, see [llms.txt](https://black-paper.rgb.tech/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://black-paper.rgb.tech/consensus-layer/3.-client-side-validation/3.3.-deterministic-bitcoin-commitments.md).

# 3.3. Deterministic bitcoin commitments

Deterministic bitcoin commitments (DBC) provide a way to create provably unique commitments inside bitcoin transactions. RGB protocol allows two types of DBC: based on taproot outputs (so-called “**tapret**”) and based on `OP_RETURN` outputs (so-called “**opret**”), useful for old hardware which doesn’t support taproot.