### \label

\label{key}

A \label command appearing in ordinary text assigns to the key the number of the current sectional unit; one appearing inside a numbered environment assigns that number to the key.

A key can consist of any sequence of letters, digits, or punctuation characters. Upper and lowercase letters are different.

To avoid accidentally creating two labels with the same name, it is common to use labels consisting of a prefix and a suffix separated by a colon. The prefixes conventionally used are

• cha for chapters
• sec for lower-level sectioning commands
• fig for figures
• tab for tables
• eq for equations

Thus, a label for a figure would look like fig:bandersnatch.