Thanks @pmario that’s very helpful.
I notice that the headings present the “single tiddler export format” as being different than the “multiple tiddler export format”. I wonder if that’s helpful; they are in fact the same file format, but with different means of generating them and hence different numbers of tiddlers within them.
I think the way that the $:/Import tiddler is explained might be confusing. There’s a lot of detail there before one gets to the plugins tiddler format section. I think it might be clearer to explain plugins first, and then to explain how $:/Import extends the plugin format (it might also be helpful to cover the special fields that the import process uses for tracking the checkbox selection.
I don’t think it’s correct to characterise this as anything to do with “security reasons”. It is more of an encoding issue: we need to make sure that there is no closing </script> tag within the data we are storing in the script tag.