How can I manage a creation of a custom sub-tasks?

[Casper]

I have:

Issue Type 'Story'                                ( Level 0 )
Custom Issue Type 'Urgent'               ( Level 0 )

Issue Type 'Sub-Task'                          ( Level -1 )
Custom Issue Type 'Sub-Urgent'.       ( Level -1 )

I want to have the option to create 'Sub-Tasks' only into 'Story'
Also, the same with 'Sub-Urgent' only into 'Urgent'

Because now I can create both sub-issues into both issues level 0.

[John Funk · Accepted solution]

Hi Casper,

You do not have ability to control which standard issue types that a sub-task can be associated with. 

[Casper]

Hi John,
Understood.

Thank you!