How to reference Family Revision

I cant figure out how to reference a family revision.

I have tried a number of ways such as:

```
"-family=familyname:2"
```

and everytime the logs return with:

Error listing tasksInvalidParameterException: family must match ^[a-zA-Z0-9\\-_]+$\n\tstatus code: 400

thanks

The issue does not name a file or test. Start by checking how the CLI handles the family argument and compare it with the ECS task-definition family and revision syntax; done means documenting the supported way to reference a family revision and confirming it avoids the reported validation error.

Written by the indexing model from the issue text.