I have seen customers defining script that looks like this:
MyField.myCustomProperty = "hello world";
The non-strict mode of variable management will continue to be supported, but I do not recommend relying on those behaviours. I recommend strict scoping for a couple of reasons:
- Bug fixes: We have branched our code internally to take one path for strict scoping (variable cleanup) and a separate path for non-strict scoping. Going forward, only the strict scoping code path will get script bug fixes.
My preferred alternative is to use form variables on subforms and the desc or extras elements on fields as described in a previous post.