# TLV Rust > [Type-Length-Value](https://en.wikipedia.org/wiki/Type-length-value) c The type and length are fixed in size (typically 1-4 bytes), and the value field is of variable size. These fields are used as follows: **Type** A binary code, often simply alphanumeric, which indicates the kind of field that this part of the message represents; **Length** The size of the value field (typically in bytes); **Value** Variable-sized series of bytes which contains data for this part of the message. ## Documents - [TLV](https://github.com/Jhuster/TLV) stars:115 - [https://github.com/lexxvir/tlv-parser](https://github.com/lexxvir/tlv-parser)