This character is a Other Symbol and is commonly used, that is, in no specific script. The character is also known as vote.
The glyph is not a composition. It has no designated width in East Asian texts. In bidirectional text it acts as Other Neutral. When changing direction it is not mirrored. U+1F5F3 offers a line break opportunity at its position, except in some numeric contexts.
The CLDR project calls this character “ballot box with ballot” for use in screen reading software. It assigns these additional labels, e.g. for search in emoji pickers: ballot, box.
This character is designated as an emoji. It will be rendered as monochrome character on conforming platforms. To enable colorful emoji display, you can combine it with Glyph for U+FE0FVariation Selector-16: 🗳️ See the Emojipedia for more details on this character’s emoji properties.
The Wikipedia has the following information about this codepoint:
A ballot box is a temporarily sealed container, usually a square box though sometimes a tamper resistant bag, with a narrow slot in the top sufficient to accept a ballot paper in an election but which prevents anyone from accessing the votes cast until the close of the voting period. A ballot drop box allows voters who have received a ballot by mail to submit it for counting in a self-service fashion. In the United States, ballot boxes are usually sealed after the end of polling, and transported to vote-counting centers.