| Breeding Pairs | Winter/Passage | |
| Very rare | 1-10 records in total since 1962 | |
| Rare | less than annual | less than annual |
| Very scarce | 1-10 per year | 1-20 per year |
| Scarce | 11-100 | 21-200 |
| Fairly common | 101-1000 | 201-2000 |
| Common | 1001-5000 | 2001-10,000 |
| Very Common | 5001-30,000 | 10,001-60,000 |
| Abundant | 30,000+ | 60,000+ |
See Birds of Sussex page 82 for more information on the above.
| R | resident, breeds |
| BV | breeding visitor, but not resident (usually a summer visitor) |
| SV | summer visitor, but does not breed |
| WV | winter visitor |
| PM | passage migrant (spring and autumn) |
| SpV | spring visitor |
| AV | autumn visitor |
| V | vagrant |
Where abundance differs according to season the values are separated by slash e.g. scarce/commom R/WV for Cormorant denotes scare resident breeder and common winter visitor.
| WB | record published by Walpole-Bond (up to 1936), sometimes in [ ] |
| dFH | record specifically included in des Forges and Harber (up to 1960-61) |
| >> | attempted reconciliation with des Forges and Harber's totals |
| * | published in relevant South Eastern Bird Report (1937-1947) or Sussex Bird Report (1948-present) |
| *82 | published in Sussex Bird Report for 1982 etc |
| */*92 | details published in relevant bird report but subsequently amended |
| × | record published in relevant British Birds Rarities Report (1958-present) |
| ×91 | record published in 1991 British Birds Rarities Report etc. |
| [ ] | record no longer considered acceptable or of suspect origin |
| HR | 'Hastings Rarity' see British Birds 55:229-384. These records were excluded by des Forges and Harber |
| † | record awaiting acceptance by relevant committee |
| ‡ | record not submitted to relevant committee, but considered genuine |
| BoMNH | Booth Museum of Natural History (followed by individual catalogue number) |
| ES | East Sussex |
| WS | West Sussex |