There are five levels of status used to indicate the likelihood of encountering a species in a given state or province. The first three categories are used for regularly occurring species that are reliably present in appropriate season and habitat. The last two categories are used for species that are not always present and not expected, even in prime habitat and season.
C Common – Common, numerous, expected on every outing, although this might only be true in part of the selected state or province.
U Uncommon/Local – Uncommon, Scarce or local, generally present and expected, but not necessarily seen on each outing and/or takes some extra effort to locate and/or expected only in a small part of the selected state or province.
S Scarce/Very local – Occasional, or very local, not always present (or present in very small numbers in limited area) but still more or less expected and predictable in occurrence. Scarce/local breeders can generally be found readily by traveling to a known location. Scarce/local migrants take luck and/or extra effort to locate, and are worth mentioning to other birders.
R Rare – not always present, recorded annually but only a few times a year or less, averaging more than one a year in recent years; occurrence may be predictable to some extent, but not reliable. Always worth reporting to other birders, and should be documented with photos and notes.
V Very rare– Extremely rare, accidental; fewer than ten records (or no records) in the last 20 years or so; many years may pass without a confirmed record. You are very unlikely to find these species. These should be carefully documented with photos and notes, and are always worth reporting to other birders as quickly as possible.