| Subject | English | Czech |
| comp., MS | null character | znak Null (" A character code with a null value; literally, a character meaning "nothing." Although it is real in the sense of being recognizable, occupying space internally in the computer, and being sent or received as a character, a NUL character displays nothing, takes no space on the screen or on paper, and causes no specific action when sent to a printer. In ASCII, NUL is represented by the character code 0. ") |
| comp., MS | null field | prázdné pole (" A field containing a Null value. A null field isn't the same as a field that contains a zero-length string (" ") or a field with a value of 0.") |
| comp., MS | null field | pole s hodnotou Null (" A field containing a Null value. A null field isn't the same as a field that contains a zero-length string (" ") or a field with a value of 0.") |
| comp., MS | null key | nulový klíč (A null value that is encountered in a key column) |
| comp., MS | null modem | nulový modem (Special cabling that eliminates the modem's need for asynchronous communications between two computers over short distances. A null modem cable emulates modem communication) |
| comp., MS | null pointer | nulový ukazatel (A pointer to nothing: usually a standardized memory address, such as 0. A null pointer usually marks the last of a linear sequence of pointers or indicates that a data search operation has come up empty) |
| comp., MS | null reference | nulový odkaz (In C++, a reference that has not been assigned an object) |
| life.sc. | null segregant | negativní segregant |