Tag for variables.
If you will be retrieving the solution to your model in JSON format, you should define a tag for every variable that you plan to retrieve solution information for. Each variable tag must be unique, and only tagged variables will appear in the JSON solution string. Tags must consist of printable US-ASCII characters. Using extended characters or escaped characters will result in an error. The maximum supported length for a tag is 10240 characters.
For examples of how to query or modify attributes, refer to our Attribute Examples.