This thread ("7TP Bug?") in the TO&E forum already covers the item (and concludes that there should be no S/D in early Polish tanks).
In future - if you have an equipment question, then please address it in its own thread and in the TO&E sub-forum, rather than drifting from the original thread (which in this case was about retreaters failing morale tests). This makes it much easier to find the thing again in the future, should it need re-reading for reference (e.g. when working through OOB mods for the next release etc.).
Cheers
Andy