What ☰ and ≡ mean
The three stacked lines ☰ are officially the trigram for heaven (U+2630), one of the eight trigrams ☰ ☱ ☲ ☳ ☴ ☵ ☶ ☷ from the I Ching, the ancient Chinese book of divination. Each trigram stacks three solid or broken lines, and ☷ (earth) is the opposite of ☰. The two-line digrams ⚌ ⚍ ⚎ ⚏ come from the same tradition.
Today most people know ☰ as the "hamburger" menu icon in apps and websites, which is why it is handy for writing instructions like "tap ☰ then Settings". ≡ is the math sign for "identical to" or "congruent to", and it also shows up as a menu or drag-handle icon.
Horizontal line characters
The box-drawing lines ─ (light), ━ (heavy) and ═ (double) have no gaps at the ends, so a row of them makes one continuous line. Dashes are different: —, – and ― leave small gaps between copies and are meant for punctuation, so see the dash symbol and long dash symbol pages for those.
For lines above or below text, use ‾ (overline) or _ and ‗ (low lines). ﹏ and 〰︎ make wavy lines, and ┄ ┈ ╌ make dashed ones. To stack lines vertically instead, see the line symbols page.
How to make a horizontal line
In Microsoft Word, type three characters on an empty line and press Enter: --- gives a single line, ___ a thick line, === a double line, *** a dotted line, ~~~ a wavy line and ### a triple line. In Google Docs, use Insert > Horizontal line. In Markdown, --- on its own line becomes a divider.
Where there is no formatting, such as Instagram captions, Discord messages or plain emails, paste a ready-made line from above. On Windows, Alt + 196 types ─ and Alt + 205 types ═. For decorated lines with stars, hearts and flowers, browse the divider symbols.