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NOTE: Only users with the granted permission to manage Scheduled Issues can access that table. JIRA Administrators can set permissions in the Access Manager.
You can create new Scheduled Issues here and manage Scheduled Issues created by yourself or shared from other users. You can access managing options by choosing More option next to each Scheduled Issue and choosing one of the following options:
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Location of "More" link (1) and additional line with options getting active, when at least one of issues gets selected (2):
As one can see, any already existing scheduled issue has such "More" link present.