The Federal Communications Commission (FCC) has granted a total of 79 licenses and call signs in the category of Restricted Operator license in Frederick, Maryland. Select a call sign from the table below to view its details such as the date of authorization, expiration date, service description, and so forth.
| Call Sign | License Holder Name | Date of Authorization |
|---|---|---|
| RL00008562 | Cesa, Carlo F | 2012-08-21 |
| RL00014068 | Jayaseelan, Vijay Wesly George | 2018-06-13 |
| RL00014093 | Roman Ganvini, Diego J | 2018-06-21 |
| RR00000762 | KULINA, STEPHEN P | 2001-06-09 |
| RR00004603 | Wilkins, Robert A | 2002-02-20 |
| RR00005880 | Baccetti, David M | 2002-05-03 |
| RR00009103 | Miller, Mark P | 2002-11-05 |
| RR00009219 | Torres, David E | 2002-11-09 |
| RR00017678 | BROWN, JANEY | 2004-03-16 |
| RR00022170 | Pierce, Matthew P | 2004-08-31 |
| RR00023085 | pinto, Joao O | 2004-10-08 |
| RR00023784 | Kirk, christopher J | 2004-11-06 |
| | ||
| RR00024512 | Smith III, Charles R | 2004-12-14 |
| RR00025851 | Koppanen, Markku M | 2005-02-11 |
| RR00025860 | Greene, Ryan T | 2005-02-11 |
| RR00027211 | Jacobs, David T | 2005-04-05 |
| RR00030075 | Goldberg, Stephan | 2005-07-14 |
| RR00031812 | Downs IV, Alfred B | 2005-09-27 |
| RR00033854 | van Otterloo, Ron | 2006-01-07 |
| RR00033857 | Toftestuen, Tommy | 2006-01-07 |
| RR00034466 | Borsum, Arne | 2006-02-02 |
| RR00035421 | Lasek, Ryan M | 2006-03-08 |
| RR00036688 | Gannon, Matthew T | 2006-04-25 |
| RR00038456 | Couto Mr, Claudio A | 2006-07-07 |
| RR00039227 | Willson, James D | 2006-08-11 |
| RR00040301 | Dupuie, Douglas A | 2006-09-13 |
| RR00041290 | Harrison, Jon L | 2006-10-11 |
| RR00044361 | Butler, Nathan C | 2007-01-30 |
| RR00056093 | Robertson, Nicholas E | 2008-01-26 |
| RR00063945 | Charlemagne PhD, Bernhard H | 2009-02-06 |
| RR00066187 | Martin, Talbot M | 2009-07-03 |
| RR00068018 | Geer 3, Erskine H | 2009-11-11 |
| RR00070045 | Fuller Mr, Craig | 2010-03-09 |
| RR00071781 | Shealer, Scot M | 2010-06-05 |
| RR00074535 | Van Lehn, Richard G | 2010-11-05 |
| RR00074542 | Van Lehn, Sethany A | 2010-11-06 |
| RR00077406 | WILLIAMS, ADAM S | 2011-03-25 |
| RR00082273 | Mercer, Mark | 2011-10-08 |
| RR00082959 | Tomlinson, Stephen E | 2011-11-11 |
| RR00088235 | Gregory, Edmond B | 2012-07-24 |
| RR00090616 | Reilly, Doug | 2012-11-27 |
| RR00091551 | Jones, Michael R | 2012-12-29 |
| RR00091673 | MOSES, DANIEL C | 2013-01-04 |
| RR00096783 | Gianni, Rachel L | 2013-08-27 |
| RR00100879 | Mishal, Michal | 2014-02-28 |
| RR00101185 | Farnam, Douglas S | 2014-03-12 |
| RR00102491 | Cooper, Heather C | 2014-04-30 |
| RR00102685 | Miller, Alyssa J | 2014-05-08 |
| RR00102727 | Shoemaker, David R | 2014-05-09 |
| RR00105960 | Kenagy, Randy C | 2014-09-04 |
| RR00115392 | Magro, Kelleen M | 2015-10-06 |
| RR00116754 | Diehl Jr., David S | 2015-11-21 |
| RR00119947 | DEHN, JOHN A | 2016-03-23 |
| RR00122790 | Varatharasa, Loganathan | 2016-06-29 |
| RR00127493 | Brannum, Nathaniel A | 2016-12-21 |
| RR00133381 | Tallman, Jill W | 2017-06-29 |
| RR00135898 | Elliot-Wilson Mr, Douglas R | 2017-09-21 |
| RR00139260 | Huber, Carl F | 2018-01-06 |
| RR00144935 | Reed Mr, James | 2018-06-15 |
| RR00147295 | Tallman, Jill W | 2018-08-24 |
| RR00147508 | Caywood, Malinda A | 2018-09-01 |
| RR00153518 | Greene, John D | 2019-03-05 |
| RR00153664 | Mrazik, Thomas C | 2019-03-08 |
| RR00154109 | Kissner, Mark E | 2019-03-20 |
| RR00155051 | Smith, Gary W | 2001-04-19 |
| RR00157761 | Hurley, Lindsey | 2019-06-20 |
| RR00160791 | Pressimone, Michael C | 2019-09-12 |
| RR00162557 | Vilschick, Eli M | 2019-11-05 |
| RR00162594 | cilliers, carlo r | 2019-11-05 |
| RR00165774 | Piersall, Mark A | 2020-02-04 |
| RR00166453 | Chiang, Jay M | 2020-02-20 |
| RR00176866 | Loeper, Lacey | 2021-06-23 |
| RR00177380 | Fitch, Anthony E | 2021-07-08 |
| RR00178401 | Joao, James T | 2021-08-03 |
| RR00187133 | HART, EVERETT T | 2022-03-08 |
| RR00196670 | Thomas III, Gregory D | 2022-09-24 |
| RR00198557 | Artusio, Brian | 2022-11-01 |
| RR00201999 | Hangartner, Michael K | 2023-01-20 |
| RR00204510 | Kidambi, Raman | 2023-03-07 |
