snapshot

Captures the accepted values, choice selections and field flags at one instant. A renderer can keep this copy through a suspended or repeated draw, so a script cannot change the form halfway through constructing its appearances (ISO 32000-1, 12.7.3.3). All state and revision counters are copied together under the same lock.

The copy can be edited and reset independently. It starts with the same revision and fieldRevision values, but has no change listeners. It still reads unchanged fields and their defaults from the same document, which must remain open while the copy is used; this does not clone or save the document.