| SID | NAME | ORIGINALS | QUOTED |
|---|---|---|---|
| 235 | UJCS | 111 | 0 |
| 2619 | UJCS JT | 2 | 0 |
| 14742 | UKCSC Postal Round | 0 | 1 |
| 11136 | UPJS-25 C | 2 | 0 |
| 4934 | US Chess Association | 1 | 0 |
| 2266 | US Chess Federation | 6 | 0 |
| 17457 | US Chess Problem Bulletin | 2 | 0 |
| 788 | US Problem Bulletin | 698 | 22 |
| 8843 | US Problem Bulletin TT | 1 | 0 |
| 16576 | USA National Chess Federation | 1 | 0 |
| 5091 | USA National Chess Federation 01. Ty. | 4 | 0 |
| 454 | USCF | 5 | 0 |
| 5304 | USCF 001. Ty. | 2 | 0 |
| 1456 | USSR | 1 | 0 |
| 1165 | USSR Championship | 82 | 0 |
| 14782 | USSR Chess Federation | 4 | 0 |
| 16014 | USSR Physical Culture Ty. | 1 | 0 |
| 17422 | USSR Sports Commitee (Theme 1) | 1 | 0 |
| 3139 | USSR Sports Committee | 7 | 0 |
| 1228 | USSR Team Championship | 22 | 0 |
| 3971 | USSR-50 JT | 2 | 0 |
| 746 | UV CSTV | 144 | 0 |
| 5982 | UV CSTV TT | 5 | 0 |
| 1696 | Uber Land und Meer | 27 | 1 |
| 5886 | Uchitelskaya gazeta | 1 | 0 |
| 15907 | Uchta | 1 | 0 |
| 13957 | Udartsev JT | 2 | 0 |
| 4153 | Udartsev-65 JT | 6 | 0 |
| 3146 | Uder | 11 | 0 |
| 13319 | Udvalgte Skakopgaver | 3 | 0 |
| 1513 | Uj Magyarsag | 9 | 0 |
| 3034 | Uj Nemezdek | 172 | 0 |
| 16480 | Uj Nemzedek | 4 | 0 |
| 11077 | Uj Szo | 1 | 0 |
| 3272 | Uj. Magyarsag | 1 | 0 |
| 2863 | Ujevi Lap | 1 | 0 |
| 7416 | Ujevi udvozlet | 1 | 0 |
| 3515 | Ujsag | 110 | 0 |
| 3943 | Ukraine | 3 | 0 |
| 6022 | Ukraine Album 1999 | 0 | 10 |
| 5930 | Ukraine Album 2003 | 0 | 8 |
| 17143 | Ukraine Championship | 1 | 0 |
| 5296 | Ukraine Emigration-100 JT | 1 | 0 |
| 10865 | Ukraine Federation Ty. | 1 | 0 |
| 3942 | Ukraine KFS Ty. | 3 | 0 |
| 59 | Ukraine Skaksekt. | 1 | 0 |
| 2100 | Ukraine Sports Committee | 8 | 0 |
| 4748 | Ukraine Sports Committee TT | 2 | 0 |
| 2101 | Ukraine Ty. | 18 | 0 |
| 6271 | Ukraine-300 JT | 1 | 0 |
| 3659 | Ukrainian Championship | 18 | 0 |
| 10252 | Ukrainian Federation | 1 | 0 |
| 3655 | Ukrainian Folk Crafts | 7 | 0 |
| 3231 | Ukrainian Republic Ty. | 3 | 0 |
| 122 | Ukrainian Ty. | 7 | 0 |
| 8367 | Ukrainische Schachsektion | 1 | 0 |
| 15686 | Ukrainske Slovo | 1 | 0 |
| 6345 | Ukrainski Resp. Konk. | 1 | 0 |
| 17065 | Ukrainski konkurs malofigurnakh zadach | 1 | 0 |
| 11846 | Ukrainskogo Kfs | 1 | 0 |
| 7948 | Ukrajina | 1 | 0 |
| 7874 | Ukrajinski Sovjet | 1 | 0 |
| 13067 | Ukran Radio versenye | 1 | 0 |
| 14817 | Ukrinische SSR-60 JT | 1 | 0 |
| 15440 | Ukroshyenie Shakhmatnogo Pegasa (Vladimirov, YG) | 0 | 88 |
| 491 | Ulehla MT | 2 | 0 |
| 4811 | Ultima Ora | 2 | 0 |
| 16086 | Ulyanovsky komsomolets | 1 | 0 |
| 4115 | Umenie 64 | 92 | 2 |
| 3796 | Umnov MT | 3 | 0 |
| 17440 | Una splendente meteora nel problemismo Italiano del 900 | 3 | 0 |
| 13281 | Under Dusken | 1 | 0 |
| 624 | Une premiere tige | 1 | 0 |
| 1650 | Unikonzum | 2 | 0 |
| 1807 | Union | 20 | 0 |
| 17528 | Union Democrat | 1 | 0 |
| 3543 | Union des Problemistes de France (UPF) | 16 | 0 |
| 5876 | Union des Problemistes de France TT | 3 | 0 |
| 8840 | Unique Chess Problems | 1 | 0 |
| 5736 | Unitas Chess Club | 2 | 0 |
| 4425 | Unitas JT | 1 | 0 |
| 3284 | United States Chess Association | 2 | 0 |
| 10025 | University YU Champ. | 1 | 0 |
| 16034 | Universum | 5 | 0 |
| 715 | Unpublished | 201 | 0 |
| 12614 | Unterfrank Arbeiter Zeiting | 4 | 0 |
| 17239 | Unterfrankische Arbeiter-Schachzeitung | 10 | 0 |
| 16514 | Unterfrankische Schachzeitung | 1 | 0 |
| 16764 | Unveroffentlicht | 1 | 0 |
| 15974 | Uperad | 1 | 0 |
| 15937 | Upsala | 1 | 0 |
| 3012 | Upsala AST | 1 | 0 |
| 8491 | Upsala Allmana Schacksallskap | 4 | 0 |
| 2480 | Upsala Allmana Schacksallskaps JT | 3 | 0 |
| 432 | Upsala Nya Tidning | 15 | 0 |
| 2229 | Upsala Schacksallskap | 10 | 0 |
| 15280 | Upsala Schacksallskap TT | 1 | 0 |
| 3562 | Upsala-Posten | 1 | 0 |
| 9229 | Upsalai Sakkor | 2 | 0 |
| 15384 | Ur hans sammlung | 1 | 0 |
| 5266 | Ural Miniature Ty. | 1 | 0 |
| 10901 | Ural Ty. | 1 | 0 |
| 1056 | Ural-sibir - Dalni Vostok | 1 | 0 |
| 17617 | Uralski Jubilee | 2 | 0 |
| 4393 | Uralski Problemist | 1537 | 123 |
| 1011 | Uralski Problemist TT | 2 | 0 |
| 15470 | Uralski Problemist-20 JT | 21 | 0 |
| 5906 | Uralski Rabochi | 4 | 1 |
| 3953 | Uralski Skazi | 48 | 0 |
| 4846 | Uralski Skazi TT | 2 | 0 |
| 1032 | Uralski Skazi-90 JT | 2 | 0 |
| 17382 | Uralsky Problemist-25 JT | 1 | 0 |
| 2005 | Urania | 13 | 0 |
| 2006 | Urania TT | 5 | 0 |
| 4317 | Urania-80 JT | 4 | 0 |
| 17602 | Uris MT (Problemas) | 16 | 0 |
| 17344 | Uris-60 JT (Problemas) | 38 | 0 |
| 5315 | Ursic MT | 1 | 0 |
| 16477 | Uruguay | 1 | 0 |
| 16300 | Ustredni Jednota Ces. Sachistu | 15 | 0 |
| 4598 | Ustredni jednoty Cesk. Sachistu JT | 1 | 0 |
| 17258 | Utarova-20 JT (Kudesnik) | 30 | 0 |
| 2700 | Utrecht Courant | 2 | 0 |
| 2749 | Utrecht Dagblad | 21 | 0 |
| 4919 | Utro | 2 | 0 |
| 962 | Uusi Aura | 4 | 0 |
| 16289 | Uusi Suometar | 2 | 0 |
| 351 | Uusi Suomi | 17 | 0 |
| 17301 | Uzbek Replublic 02. Ty. | 5 | 0 |
| 16382 | Uzbek SSR-30 JT | 4 | 0 |
| 2508 | Uzbekistan Committee for Physiculture & | 1 | 0 |
| 10343 | Uzbekistan Federation | 2 | 0 |
| 3653 | Uzbekistan Sports Committee | 18 | 0 |
| 7892 | Uzbekistanska Sutaz | 1 | 0 |
| 60 | Uzbekistanskaya Pravda | 6 | 0 |
| 13425 | Uzdavinynas | 3 | 0 |
Developed and maintained by Brian Stephenson.
Implemented with HTML5, MySQL, Perl (with, inter alia, CGI::Simple, HTML::Template & XML::LibXML) &
CSS/Javascript (jQuery, Bootstrap & DataTables).