noun
open element
Computing term for an element in a markup language (e.g., HTML, XML) that has a start tag but no corresponding end tag, or is self-closing.
HTMLでは、<br>は開いている要素の一つです。
In HTML, <br> is one of the open elements.
Compound of 開いている (hiraiteiru, 'open') + 要素 (yōso, 'element'). A direct translation of the English computing term 'open element'.