This message is generated when the indicated symbol is not recognized.
This message can appear if the name of the symbol is not spelled correctly or if the name given is not a syntactically valid symbol name.
If the context of the symbol is not included in $Context or $ContextPath, then the context must be included in the name or the symbol will not be found.
Off[message] switches off the message; On[message] switches it on. For example: Off[General::notfound].
Examples
Basic Examples(1)
The name given is not a syntactically valid symbol name (symbol names cannot include square brackets):