There is Victorian era typewriter markup. This uses *bold* and /italics/, though 'italics' and _italics_ are/were also used. The Typesetter was also supposed to figure ' " from context and also some typewriters had no 0 or 1, so O and I was used and changed by typesetter. The -omit this- became
strikeout and sometimes _text_ meant heading, bold or underline, but many early typewriters had no _. Some had no ! and used l <backspace> . and the £ might sometimes be L <backspace> - or =, similarly for $ and Yen. The \ | ` ¦ ¬ { } [ ] ~ and all quotation marks were missing.
This led to
Markdown and
AsciiDoc
There is also BBCode (more typing, but more features as it's a subset of HTML using [ ] instead of < >, might as well use HTML/XML) and
Wiki text. While Wiki text allows a lot of formatting, it thus has a longer learning curve.
There is also LaTex, but it's even more learning.
The USA IBM PC keyboard is based on a 1930s ASR Teletype (used for telegrams, telex, RTTY, punching morse tapes etc), which is why the @ was used for email, as early computers from 1940s to 1970s often used a teletype rather than CRT and keyboard.