Using the native APIs in Sitefinity has been a solid framework to create new features and solidify an already fantastic product. Once in a while you hit something new that is not documented and you scratch your head on what it could be for :)
Since the beginning of the new architecture of Sitefinity in version 4.0, we are used to the 3 main ContentLifeCycle states (Master, Live and Temp) and with the introduction of the Recycle Bin, we got a new 4th state which is "Deleted" but if you look closer lately, you might see a new cousin in the drop down that is not documented on the Sitefinity site or in any release notes and that is "PartialTemp"
So what the heck is PartialTemp?
Think of it as the "Concurrent content editing in Multilingual".
When a content item is checked out for editing, Sitefinity lifecycle creates the item in Status "Temp" indicating that all translatable fields of the item are locked for the current language and all non-translatable fields are locked for all languages. Only one "Temp" item is allowed per content item.
At this time, when there is already a "Temp" for the item, all subsequent edits of the item in other languages create items with status "PartialTemp", which allows to update only localizable fields of the content item.
In other words each content item could have only one "Temp" item and "Temp"/"PartialTemp" per language, in order to be able to translate item in all languages at the same time.
Thanks to Peter Filipov and the Sitefinity team in Sofia for the heads up
Hope this helps someone