Phal NOID with Dry Black Spots Under Leaves

[WaterWitchin]

To me, it looks more like a mechanical injury (like leaf was rubbing on lip of pot). Hard to tell, since it's recently repotted and appears to be tied up with a bit of twine.

I am very far from an orchid expert, so hopefully someone more knowledgeable will chime in. I also tend to plant my phals a bit deeper in the pot. Whether that's right or wrong, I don't know. It works for me.

Out of curiosity, why ARE they all tied up with a bit of twine?