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In order to add checklist items, just click on the Add a new item input and start typing. You can add as many checklist items as you wish. You can approve the addition of the item with an [Enter] or via the checkmark button available below the input on the right-hand side.
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The limit of the checklist items that you can add to one checklist is 32KB and this is dictated by the Jira guidelines. If this is a problem for you, you can add another checklist in the same Jira issue.
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Edit checklist title and items
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