Vote variation in which the voter is entitled to allocate a fixed number of votes (N) over a list of M contest options or write-in options, with the constraint that at most 1 vote may be allocated to a given contest option. This usually occurs when multiple seats are concurrently being filled in a governing body such as a city council or school board where candidates contend for at-large seats. The voter is not obliged to allocate all N votes. 1-of-M is N-of-M voting where N = 1.
Source: Election Terminology Glossary - Draft, National Institute of Standards and Technology (NIST), https://pages.nist.gov/ElectionGlossary/