> For the complete documentation index, see [llms.txt](https://docs.sannybuilder.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.sannybuilder.com/troubleshooting/errors/0068.md).

# 0068: Forbidden character in identifier

The compiler finds an forbidden character in a [variable](/language/data-types/variables.md) name, [label](/language/data-types.md#labels), or any other identifier. Only digits, letters and the underscore (`_`) are allowed.

**Possible solutions:** update the name to include only allowed characters.