| Subject | English | Bulgarian |
| construct. | envelope curvature | кривина на черупка |
| comp., MS | envelope journaling | пликово регистриране (A type of message journaling in which the original unaltered message is included as an attachment in the journal report) |
| construct. | envelope of rotation | ротационна черупка |
| commun., el. | peak envelope power | върхова мощност |
| commun., el. | peak envelope power of a radio transmitter | върхова мощност |
| construct. | pressing of envelope into ground | смачкване на черупка |