Looking in the docs I don’t see the index property (used in control sets) as a property of the WebTextField. In the IDE it certainly acts like a property.
Should it be in the docs? Is it somewhere else? I don’t see control set in the docs.
Yes, Control Set Index. It works exactly like the desktop. I’m using it. Works fine. Etc.
But, when I look in the language reference, I don’t see any sign of it. The link that Paul provided nicely describes how to use control sets. I would expect some sort of reference/see also/for more info in the LR either on the control or the WebControl as appropriate.