# Custom Graffiti By default, Charon adds a `charon/-` graffiti to all block proposals. This can be customized using the `--graffiti` and `--graffiti-disable-client-append` CLI flags. The `--graffiti` flag accepts either: * A single string, which will be used by all validators, or * A comma-separated list of strings, allowing each validator to have a unique graffiti (one string per validator). When possible, Charon automatically appends an Obol signature (`OB`) and the specific consensus client type used (``) to the end of the custom graffiti. This behavior can be disabled by setting the `--graffiti-disable-client-append` flag. {% hint style="info" %} The graffiti field in block proposals has a maximum size of 32 bytes. {% endhint %} --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://docs.obol.org/advanced-and-troubleshooting/advanced/custom-graffiti.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.