| Prefixo | Organização | Intenção | Site da Internet | Contato | Inscrito |
|---|---|---|---|---|---|
| UB | Logisoft | ubStyleForm and others | www.logisoft.it | Uberto Barbini | 07-Jun-1999 |
| UBE | Chris Ueberall | 26-Oct-1999 | |||
| UC | Dave Jewell | Uncommon Controls; Reserved | Dave Jewell | 01-Feb-1999 | |
| UDC | Various | www.edye.wattle.id.au/hobbies/prog/delphi/ | Donovan J. Edye | 04-Jul-1999 | |
| UF | Ultra Force Development | www.ultraforce.com | J. Munnik | 13-Apr-2000 | |
| UI and UIL | Unlimited Intelligence Limited. | Reserved | www.uil.net | Tim Sullivan | 14-Sep-1998 |
| umf | Unlimited Intelligence Limited | The UIL Merge Framework | www.uil.net | Tim Sullivan | 05-Aug-2001 |
| UNI | Unicode Informatica | Unicode Library | www.unicode.pop.com.br | Marcelo Costa | 29-Sep-2003 |
| UNT | Unicode tools | Arian Lashkov | 02-Nov-1999 | ||
| UO | UnitOOPS Software | OLE Drag and Drop Components; OLE | www.unitoops.com | Jim O'Brien | 04-Aug-1998 |
| UP | Upscene Productions | www.upscene.demon.nl | Martijn Tonies | 19-Apr-1999 | |
| upf | Unlimited Intelligence Limited | The UIL Plugin Framework | www.uil.net | Tim Sullivan | 05-Aug-2001 |
| UQ | TuqIPEdit, TuqMacEdit | Daniel Nakasone | 20-Nov-2001 | ||
| uq | Tuqmacedit Tuqipedit | Daniel Nakasone | 04-Dec-2001 | ||
| urc | Urban Cohort | PhonePad | Centurion | 23-Mar-2005 | |
| urs | Raabe Software | class, unit and interface names | www.uweraabe.de | Uwe Raabe | 17-Mar-2017 |
| URU | URU Software | Reserved | www.urusoft.com | Hadi Harir | 06-Apr-1999 |
| US | Unley Software | misc tools | www.unley.com | Graham Pitson | 05-May-1999 |
| usf | Unlimited Intelligence Limited | The UIL Security Framework | www.uil.net | Tim Sullivan | 05-Aug-2001 |
| UTC | Ultratech Creations | reserved | www.UltratechCreations.com | Michael H. | 10-Apr-1999 |
| utl | ThinkTech Visions, Inc. | Reserved | www.thinktechvisions.com | Patrick Choiniere | 19-Dec-2001 |
| UTS | Universal Tax Systems, Inc. | UTS components | www.uts.com | Calin Borcan | 10-May-1999 |
| uts | Unlimited Intelligence Limited | www.uil.net | Tim Sullivan | 11-Oct-2001 | |
| UX | ULTRAX, Inc | ULTRAX Components and Test Application Framework | www.ultraxinc.com | Chris Lincoln | 24-Jul-2001 |
| U_ | US Group | Reserved; Reserved | www.usgroup.com | Richard Morris | 01-Feb-1999 |