Never though transformers would be so confusing to many - I found about a dozen similar questions here. Adding mine to the pile.
Here are the datasheets for 3 Transformers: 750313975, 750313445 and 750311088. They all have 2 secondary coils, but the drawings are different. Is that supposed to reflect the physical coil arrangement on the core somehow?
The second says it "allows" to parallel two secondaries. But the pinout is exactly as the first one, so what's the difference?
More than that, the third one says "customer to tie terminals on PCB", which I understand as we must tie them together. A rather weird requirement.
Finally, the wire diameter or current rating is nowhere to be found. Should I assume that it would be at least close to saturation current?
To clarify the question: Is there any specific convention for drawing coils I am not aware of?
All my life I used to draw transformers as the one on the first picture, with primary and aux coils on the left, secondaries on the right, all lined up along the core lines.