How to create a custom filed which should accept only Jira key

[tech force]

Need a way to create custom filed in Jira and enforce that it should accept only - valid Jira key.

For ex, from number of tasks, we need a tracking for which Story the task belonged to.

I know we can link, but looking a way if any custom filed can allow us to do this.

[Payne]

We use a free add-on that is available only for server, not cloud, so it unfortunately isn't something you can use, but I mention it here for others' sake.

https://marketplace.atlassian.com/apps/1216498/easy-links-for-jira?hosting=server&tab=overview 

[Alexey Matveev]

Hello,

It is not possible for Cloud to have a field, where you choose an issue key.

[tech force]

Thanks Alexey!  I thought the way epic link provides a way to link with one type of Jira key, same way we can have another field just to have any valid Jira key.

[Nic Brough -Adaptavist-]

You're pretty much limited to issue links on Cloud.  (Although the server fields seem to serve to just confuse people and cause performance issues)