Separated sextant tile 145

It marks cells 1, 4, and 5 in a six-cell tile. The tile is a 2-by-3 grid: two columns and three rows, numbered across each row from top to bottom.

Here, “sextant” means a six-part mosaic. In teletext, neighboring block graphics could be arranged to build a larger low-resolution image from text characters.

Why does this mosaic leave gaps?

The gaps identify its separated graphics mode. In broadcast teletext, cells could touch in contiguous mode or have background colour around and between them in separated mode.

Teletext—broadcast pages of text and simple graphics—developed in the UK in the early 1970s. The 1976 Broadcast Teletext Specification described the 2-by-3 grid and separated mode. A Unicode proposal in 2021 called for distinct characters so emulators and existing files using private-use mappings could preserve that mode. The proposal’s authors also gave the patterns descriptive names: the numbers identify the cells that are on.