| Subject | English | Bulgarian |
| logist. | class R car | хладилен вагон (алешаBG) |
| coal., chem. | D.E.R.V.-fuel | газьол |
| chem. | ponceau 4 R | Понсо 4R |
| environ., chem. | R-22 | хлордифлуорметан |
| comp., MS | R&B | ритъм енд блус (One of the music genres that appears under Genre classification in Windows Media Player library. Based on ID3 standard tagging format for MP3 audio files. ID3v1 genre ID 14) |
| patents. | R&D&I | научни изследвания, развитие и иновации |
| chem. | R-phrases | R фрази |