symbols, acronyms & abbreviations

mL

milliliter: milli- + liter. Used without a period. A symbol in SI, the International System of Units.

The symbol L was adopted in the United States (as an alternative to "l") to avoid confusion between the numeral "1" and the lowercase letter "l", since these characters are the same or very similar in many fonts, includingtypewriting. "L" was approved as an alternative symbol by the CGPM in 1979 (Resolution 6).

Metric System of Measurement; Interpretation of the International System of Units for the United States.
Federal Register Dec. 20, 1990. (55 FR 522 42-522 45).

American National Standard ANSI/IEEE Std 268-1982, Metric Practice.