The designator current refers to the note which Tinderbox is currently exporting. Where a note is exported to its own page, current is the same as this.
However, if a note includes children or other notes, current differs from this in the included notes reflecting the note actually being processed (and not the note that initiated the export). It is extremely useful for boilerplate-style includes that need to use attribute values from the calling note.
For instance, if 'Note X' is calling an ^include^ of the text of 'Note Y' and the latter makes a code reference to the note title then, in the include's code:
^value($Name)^ gives Note Y.
^value($Name(current))^ gives Note X.
Note that, when it appears outside an export template (e.g. in an agent or container action), current is synonymous with this.
Designators don't allow offset references as with attributes. Thus $Name("Some note") works but child("Some note") doesn't. If an offset designator is needed use find() instead.