| Abbreviation | Definition |
|---|---|
| SEBL | Siebel Systems, Inc. |
| SEBL | Siebel Systems, Incorporated (de-listed) |
| SEBL | Siebel Systems, Incorporated (de-listed) |
| SECAY | Societe Europeenne de Com Class A |
| SECAY | Societe Europeenne de Com Class A (de-listed) |
| SECAY | Societe Europeenne de Com Class A (de-listed) |
| SECBY | Societe Europeenne de Com Class B |
| SECBY | Societe Europeenne de Com Class B (de-listed) |
| SECBY | Societe Europeenne de Com Class B (de-listed) |
| SECD | Second Bancorp, Inc., of Ohio |
| SECD | Second Bancorp, Incorporated (de-listed) |
| SECD | Second Bancorp, Incorporated (de-listed) |
| SECM | Secom General Corporation |
| SECQE | SECURITEK International Corporation |
| SECTE | Sector Communications, Inc. |
| SECTE | Sector Communications, Incorporated (de-listed) |
| SECTE | Sector Communications, Incorporated (de-listed) |
| SECX | S E D International Holdings, Inc. |
| SECX | SED International Holdings, Incorporated (de-listed) |
| SECX | SED International Holdings, Incorporated (de-listed) |