I would like to mention that we don't have manuals in pdf (like sybase used to do and sap continues to do for other products). For PB 12.6 we only have 3 documents as you can see in the following link: SAP PowerBuilder 12.6 – SAP Help Portal Page. For other products (like powerdesigner) they released a full set of manuals (SAP PowerDesigner 16.5 SP04 – SAP Help Portal Page). Why not for PB? (The last set of manuals is for PB 12.5.x).
This will likely help new developers to use the product!