Is there a way to assign this permission level? Currently the lowest permission level that allows adding is Contribute. Unfortunately this allows users with this level to add/edit/delete all posts in this list? How can I make it so users can add to the list, but only have the ability to edit or delete their own posts?
If this is a List and not a library then this functionality is built-in. Simply go to List Settings - Advanced - Item level Permissions and you can configure exactly this behavior
I had this problem too. I found an answer that actually works:
Create a permission level with Delete Items selected
- Site Settings > Site Permissions > Permission Levels >
- From here you can either click Add a Permission Level or click on an existing Permission Level (i.e., Contribute), scroll down to the bottom and click Copy Permission Level. Give it a name like "Contribute Delete"
Open SharePoint Designer as Admin or make sure the user account that you are signed in with has the permission to delete items)
- Click on the list that you want to use your new permission level for
- List Workflow > Type your Workflow Name > SharePoint 2010 Workflow > OK
- Click above Step 1 > Click Impersonation Step
Click inside the Impersonation Step > Action (Ribbon) > Under List Actions click "Add List Item Permissions"
Click "these permissions" > Add > Choose > User who created the Item > OK > Check your permission level that you created in Step 1 > OK > OK
Click "this list" > make sure Current Item is selected > OK > Publish the workflow
Make sure that "Start workflow automatically when an item is created" is checked in the Start Options
I'm not sure if this is helpful or not.
You can configured a custom Permission Level (not to be confused with Item Level Permissions).
Site Collection --> Site Settings --> Site permissions --> Permission Levels (on the Ribbon).