参考官网：COG - NCBI
| Letter | English | Chinese |
| J | Translation, ribosomal structure and biogenesis | 翻译，核糖体结构和生物发生 |
| A | RNA processing and modification | RNA处理和修饰 |
| K | Transcription | 转录 |
| L | Replication, recombination and repair | 复制，重组和修复 |
| B | Chromatin structure and dynamics | 染色质结构和动态 |
| D | Cell cycle control, cell division, chromosome partitioning | 细胞周期控制，细胞分裂，染色体分离 |
| Y | Nuclear structure | 核结构 |
| V | Defense mechanisms | 防御机制 |
| T | Signal transduction mechanisms | 信号转导机制 |
| M | Cell wall/membrane/envelope biogenesis | 细胞壁/膜/包膜生物发生 |
| N | Cell motility | 细胞运动性 |
| Z | Cytoskeleton | 细胞骨架 |
| W | Extracellular structures | 细胞外结构 |
| U | Intracellular trafficking, secretion, and vesicular transport | 细胞内运输，分泌，和囊泡转运 |
| O | Posttranslational modification, protein turnover, chaperones | 翻译后修饰，蛋白质降解，分子伴侣 |
| X | Mobilome: prophages, transposons | 可动基因组：原噬菌体，转座子 |
| C | Energy production and conversion | 能量产生和转换 |
| G | Carbohydrate transport and metabolism | 碳水化合物转运和代谢 |
| E | Amino acid transport and metabolism | 氨基酸转运和代谢 |
| F | Nucleotide transport and metabolism | 核苷酸转运和代谢 |
| H | Coenzyme transport and metabolism | 辅酶转运和代谢 |
| I | Lipid transport and metabolism | 脂质转运和代谢 |
| P | Inorganic ion transport and metabolism | 无机离子转运和代谢 |
| Q | Secondary metabolites biosynthesis, transport and catabolism | 次级代谢产物的生物合成，转运和分解 |
| R | General function prediction only | 仅一般功能预测 |
| S | Function unknown | 功能未知 |