on vowels are omitted. Some of the vowels are also represented using different letter combinations. BGN/PCGN A system used by the United States Board on Geographic Names and the Permanent Committee on Geographical Names for British Official Use, published in 1972. It is based on the modified 1959 Service Géographique Khmer (SGK) system. ALA-LC Romanization Tables This system (also called Transliteration System for Khmer Script), from the American Library Association and Library of Congress, romanizes Khmer words using the original Indic values of the Khmer letters, which are often different from their modern values. This can obscure the modern Khmer pronunciation, but the system has the advantage of relative simplicity, and facilitates the etymological reconstruction of Sanskrit and Pali loanwords whose pronunciation may be different in modern Khmer. The system is a modification of that proposed by Lewitz (1969), and was developed by Franklin Huffman of Cornell University and Edwin Bonsack of the Library of Congress for the library cataloguing of publications in Khmer. Example words written in each romanization system Tables of romanization systems This chart shows in full the three main systems for the romanization of Khmer: UNGEGN (or BGN/PCGN), Geographic Department and ALA-LC: Consonants 1st series 2nd series {| class=wikitable style="text-align: center;" |- ! colspan="2"| Khmer ! rowspan="2"| UNGEGN ! rowspan="2"| ! rowspan="2"| ALA-LC |- ! Fullform ! |-style="background-color:#F5E8E4" | ក || ្ក || k || k || k |-style="background-color:#F5E8E4" | ខ || ្ខ || kh || kh || kh |-style="background-color:#E4F1F5" | គ || ្គ || k || k || g |-style="background-color:#E4F1F5" | ឃ || ្ឃ || kh || kh || gh |-style="background-color:#E4F1F5" | ង || ្ង || ng || ng || ng |-style="background-color:#F5E8E4" | ច || ្ច || ch || ch || c |-style="background-color:#F5E8E4" | ឆ || ្ឆ || chh || chh || ch |-style="background-color:#E4F1F5" | ជ || ្ជ || ch || ch || j |-style="background-color:#E4F1F5" | ឈ || ្ឈ || chh || chh || jh |-style="background-color:#E4F1F5" | ញ || ្ញ || nh || nh || ñ |-style="background-color:#F5E8E4" | ដ || ្ដ || d || d || ṭ |-style="background-color:#F5E8E4" | ឋ || ្ឋ || th || th || ṭh |-style="background-color:#E4F1F5" | ឌ || ្ឌ || d || d || ḍ |-style="background-color:#E4F1F5" | ឍ || ្ឍ || th || th || ḍh |-style="background-color:#F5E8E4" | ណ || ្ណ || n || n || ṇ |-style="background-color:#F5E8E4" | ត || ្ត || t || t || t |-style="background-color:#F5E8E4" | ថ