Year 30 (XXX) was a common year starting on Sunday (link will display the full calendar) of the Julian calendar. At the time, it was known as the Year of the Consulship of Vinicius and Longinus (or, less frequently, year 783 Ab urbe condita). The denomination 30 for this year has been used since the early medieval period, when the Anno Domini calendar era became the prevalent method in Europe for naming years.

7.62 mm caliber is a nominal caliber used for a number of different cartridges. Historically, this class of cartridge was commonly known as .30 caliber, the Imperial unit equivalent, and was most commonly used for indicating a class of full power military main battle rifle (MBR) cartridges. The measurement equals 0.30 inches or 3 decimal lines, written .3" and read as Three-Line.

This is a list of dialing codes in Greece. The first digit represents type of service. 1 is used for short codes, 2 for geographical numbers (3 and 4 are reserved for that purpose too), 5 is used for inter-network routing purposes (non-dialable codes) and VPNs, 6 for mobile services, 7 is reserved for universal access numbers (not active), 8 for reduced fee services (like 800 toll-free, 801 local call, 89 dial-up and data services), 9 is used for premium rate services (901 for general purpose and 909 for adult-only services). All dialable numbers are ten digits, except for short codes (3-5 digits on the 1 range), 807-XXXX (seven digits) used for calling card access codes, and numbers on the 5 range, used for routing purposes and not dialable by end subscribers.

A vertical service code (VSC) is a special code dialed prior to (or instead of) a telephone number that engages some type of special telephone service or feature. Typically preceded with an asterisk, or * (star), key on the touch tone keypad and colloquially referred to as star codes, most are two digits in length; as more services are developed, those that use 2 or 3 as the first digit are sometimes three digits in length.

–30– has been traditionally used by journalists to indicate the end of a story. It is commonly found at the end of a press release. There are many theories about how the usage came into being, e.g. from that number's use in the 92 Code of telegraphic shorthand to signify the end of a transmission in the American Civil War era.