Regions of the first and second level are used when
the literature gives no precise location, or material from the whole
region is described, scattered among various areas which are not
indexed separately in this case.
For advice and correction we are grateful to Jörn Geister (Bern),
Bernhard Riegl (Florida) and Helmuth Schumacher (Essen).
| Code | Level 1 | Level 2 | Level 3 | Number |
| GLO | World-wide | 20 | ||
| IPC | Indo-Pacific | 55 | ||
| INO | Indian Ocean | 31 | ||
| WIO | Western Indian Ocean | 10 | ||
| SAF | South-east Africa | 61 | ||
| CEA | North-east Africa | 68 | ||
| SEY | Seychelles | 80 | ||
| MAD | Madagascar | 37 | ||
| RSE | Red Sea | 427 | ||
| SAR | South-east Arabian Peninsula | 32 | ||
| GUL | Persian Gulf | 45 | ||
| MAS | Mascarene Archipelago | 85 | ||
| CIO | Central Indian Ocean | 10 | ||
| IND | Arabian Sea | 27 | ||
| WBB | Western Bay of Bengal | 4 | ||
| MAL | Central Indian Ocean islands | 104 | ||
| SLK | Southeast India, Sri Lanka | 59 | ||
| STI | Southern temperated Indian Ocean | 9 | ||
| CIP | Central Indo-Pacific | 1 | ||
| EIO | Eastern Indian Ocean | 2 | ||
| BTW | Myanmar to western Thailand | 82 | ||
| ANI | Andaman Islands, Nikobar Islands | 19 | ||
| EII | Eastern Indian oceanic islands | 10 | ||
| CCI | Center of central Indo-Pacific | |||
| THI | Gulf of Thailand | 28 | ||
| MAY | Malaysian Peninsula | 63 | ||
| IDO | Indonesian Seas | 193 | ||
| PNG | Papua New Guinea | 52 | ||
| NCI | Northern region of central Indo-Pacific | |||
| SCS | Vietnam, South China Sea islands | 93 | ||
| PHI | Philippines | 143 | ||
| CHH | China and nearby islands | 69 | ||
| TJP | Taiwan, south-western Japan | 529 | ||
| KJP | Sea of Japan, north-western Japan | 51 | ||
| AUS | Australia | 10 | ||
| WAU | Western and north-western Australia | 59 | ||
| SAU | Southern Australia, Tasmania | 23 | ||
| EAU | Eastern Australia | 750 | ||
| NAU | Northern Australia | 12 | ||
| PAC | Pacific Ocean | 41 | ||
| NTP | Northern temperated Pacific Ocean | 5 | ||
| MIC | Micronesia | 207 | ||
| MEL | Melanesia | 106 | ||
| NZL | New Zealand | 35 | ||
| FID | Central southern Sea | 85 | ||
| POY | Polynesia | 173 | ||
| EIS | South-eastern Pacific | 12 | ||
| EPC | Eastern Mid-Pacific basin | |||
| HAW | Hawaiian Archipelago | 328 | ||
| NWA | NW American temperate waters | 69 | ||
| GOC | Gulf of California | 39 | ||
| TEP | Tropical east Pacific | 325 | ||
| SPC | SE temperate Pacific | 3 | ||
| ATL | Atlantic Ocean | 11 | ||
| NTA | North-western temperated Atlantic | 17 | ||
| NAE | North American East-coast | 68 | ||
| TWA | Tropical western Atlantic | 124 | ||
| FLA | Florida, Bahamas, Carolina | 490 | ||
| BEM | Bermuda | 111 | ||
| GOM | Gulf of Mexico | 123 | ||
| GAT | Greater Antilles | 466 | ||
| LAT | Lesser Antilles | 162 | ||
| CAR | SW Caribbean | 310 | ||
| SAN | North-eastern South America | 146 | ||
| BRZ | Brazil | 106 | ||
| ARG | Argentina | 1 | ||
| EAT | Eastern Atlantic | |||
| NWE | North-western Europe (= north-eastern Atlantic) | 265 | ||
| SWE | South-west Europe to north-west Africa | 62 | ||
| MED | Mediterranean Sea | 345 | ||
| WAF | Tropical West Africa | 32 | ||
| SMA | Southern Atlantic | 12 | ||
| ANT | Antarctic | 18 | ||