Null (SQL) (or NULL), a special marker and keyword in SQL indicating that a data value does not exist, is not known, or is missing.
Null character, the zero-valued ASCII character, also designated by , often used as a terminator, separator or filler. This symbol has no visual representation.
Null device, a virtual file that discards data written to it, on Unix systems /dev/null
Null pointer or reference (sometimes written NULL, nil, or None), an object pointer (or reference) not currently set to point (or refer) to a valid object
Null (linguistics) (sometimes zero), a segment that is not pronounced or written:
Null morpheme (or zero morpheme), a morpheme that has no phonetic form.
Null coda, the coda of syllables ending in a vowel; especially in reference to languages that forbid codas.
Null onset (or empty onset, or zero onset), the onset of syllables beginning in a vowel; forbidden in some languages.
Zero consonant (or zero consonant), a consonant letter that does not correspond to a consonant sound, but is required when a word or syllable starts with a vowel.
Null-subject language, a language whose grammar permits an independent clause to lack an explicit subject; such a clause is said to have a "null subject".
Null copula (or zero copula), a linguistic phenomenon whereby the subject is joined to the predicate without overt marking of this relationship.
