I am familiarizing myself with MF Connect, to prepare an intended synchronization.
The data flow should be uni-directional, from the Micro Focus tool SBM, to ALM. Specific type of SBM items should be transferred as ALM requirements.
Connect Version in question is 4.4.1.

I managed to set up a very simple sync between the two tools in my lab environment, by following the instructions from the SBM Connector 4.4.1 README file.
However, I deliberately ignored one portion of the README instructions, namely the following section:

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Target Item's Identifier
Configure SBM To Store Target Item's Identifier
When using an SBM data source as the hub in a connection, the SBM Application must contain an additional field to support the external unique identifier from the target data source.

It is recommended that you use an 80 character fixed-length Text field in SBM. The size can differ depending on the target's unique identifier. It is also recommended that you make this field read-only, and then override this attribute on any custom-defined Submit/Update transition.

If the SBM Data Source is used as the hub for multiple targets, then you'll need to create the same number of SBM fields to support each target. You cannot use the same SBM field when multiple targets are defined.
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The reason that I ignored this section was, that using such a field would mean writing data back to SBM - even if this would be restricted to only one data field, this should be avoided, unless technically required.

To my surprise, I found that MF Connect obviously knows the ALM counterpart for each sync'ed SBM item - even without this target item identifier field:
When I created a new item in SBM, a new requirement in ALM was created.
When I updated the same SBM item, the corresponding ALM requirement was also updated.

This raises a number of questions:

• Does MF Connect store the internal identifiers of corresponding objects behind the scenes - maybe in it's internal Derby database?
• Is the Target Item Identifier field in SBM mentioned in the README obsolete?
• Under the assumption that MF Connect stores the relevant data internally: What would be the consequences of these data being lost?
  Would all the SBM data get transferred again, causing duplication of data in the target system?