# hyphen (1-hyphen.org)

A small horizontal line that joins words or breaks a word at the end of a line. People use it in compound words like 'mother-in-law' or to clarify meaning, as in 'small-business owner' versus 'small business owner'.

## What a model may hear
- subtraction operator (programming and mathematics): interpret the character as minus, subtracting one value from another or indicating a negative number
- command flag prefix (Unix and command-line interfaces): read the following characters as options or flags for a program, as in 'ls -la'
- range indicator (regular expressions and programming): treat it as defining a character range inside square brackets, like [a-z]
- word separator in identifiers (CSS and some programming conventions): refuse to parse it as part of a variable name, since many languages require underscores instead
- line continuation marker (shell scripts and some config files): treat it as joining lines or indicating a break depending on placement and escaping

## Where people and models part ways
- Says: "Add a hyphen between those words"
  Means: Insert the punctuation mark - to connect two words
  May be taken as: Subtract the second word from the first, or treat the whole phrase as a command with flags
  Say instead: "Insert a hyphen character, the punctuation mark, between those two words"
- Says: "Use a minus sign"
  Means: Type the hyphen character on the keyboard
  May be taken as: Use the longer en-dash or minus symbol from Unicode, which may not render or parse correctly
  Say instead: "Type the ASCII hyphen character, the short dash on the main keyboard"
- Says: "Separate with hyphens"
  Means: Put hyphens between words for readability
  May be taken as: Interpret as a request to subtract or negate the words, or to create command-line flags
  Say instead: "Join the words with hyphen punctuation marks for readability"
- Says: "Dash between the numbers"
  Means: Put a hyphen between two numbers
  May be taken as: Subtract the second number from the first, or create a numeric range [a-z] style
  Say instead: "Insert a hyphen character as punctuation between the two numbers, not as a minus sign"

## Tips
- Say 'hyphen character' or 'hyphen punctuation' to distinguish from minus or dash
- Specify 'ASCII hyphen' when you need the basic keyboard character, not an en-dash or em-dash
- In code contexts, say 'literal hyphen' to mean the character itself, not an operator
- Say 'join with hyphens' rather than 'separate with hyphens' to avoid subtraction readings
- When describing command-line syntax, say 'dash or hyphen flag' to be clear you mean the prefix, not subtraction

## Often confused with
- minus: same character in ASCII but signals subtraction, not word-joining
- dash: often means en-dash or em-dash, longer and used differently in typography
- underscore: a different word-joining character, valid in most code identifiers where hyphen is not
- pipe: a vertical bar used for chaining commands, not joining words
- tilde: a wavy line used for home directories or approximation, not word-joining
- slash: a diagonal line for paths and division, not horizontal word connection