> For the complete documentation index, see [llms.txt](https://mixdao.gitbook.io/dfinity/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://mixdao.gitbook.io/dfinity/qi-internet-computer-jie-kou-gui-fan/biao-shi-ma.md).

# 标识码

就系统的大多数用途而言，标识码（例如：canister,用户和子网ID）都是二进制blob，长度在0到29个字节之间。但是，它们具有某种结构来编码特定的身份验证和授权行为。