Let's say I've got a parameter like limit. This one gets used all over the place and it's a pain to have to change it everywhere if I need to update it:

parameters:
    - name: limit
      in: query
      description: Limits the number of returned results
      required: false
      type: number
      format: int32

Can I use $ref to define this elsewhere and make it reusable? I came across this ticket which suggests that someone wants to change or improve feature, but I can't tell if it already exists today or not?