Twelfth man
Traditionally, the first substitute player who fields when a member of the fielding side is injured. In Test matches, twelve players are named to a team prior to the match, with the final reduction to eleven occurring immediately prior to play commencing on the first day. This gives the captain some flexibility in team selection, dependent on the conditions (e.g. a spin bowler may be named to the team, but omitted if the captain feels that the pitch is not suitable for spin bowling). Twenty20 (or T20) 
a form of limited overs cricket in which each team has one innings with a maximum length of twenty overs. Two
batsmans call for a probable two runs, requiring their partner to commit to a fast turn. See No, Push, Yes, Wait. U
Umpire
An official who enforces the laws and adjudicates play. One umpire stands behind the wicket at the non-strikers end, while a second (usually) stands at square leg, with the positions alternating for each over. The two on-field umpires use a system of arm signals to indicate decisions to the players and the scorer. Televised matches usually also have a third umpire to adjudicate on replays and the umpire decision review system. Umpire Decision Review System (UDRS)
(or Decision Review System, DRS)Official system to challenge certain decisions made by an umpire. The third umpire then reviews the decision using various technological aids, such as slow motion television replays, ball tracking, a snickometer etc.
Calcinosis is the formation of calcium deposits in any soft tissue. It is a rare condition that has many different causes. These range from infection and injury to systemic diseases like kidney failure. Types
Dystrophic calcification
The most common type of calcinosis is dystrophic calcification. This type of calcification can occur as a response to any soft tissue damage, including that involved in implantation of medical devices. Metastatic calcification
Metastatic calcification involves a systemic calcium excess imbalance, which can be caused by hypercalcemia, kidney failure, milk-alkali syndrome, lack or excess of other minerals, or other causes. Tumoral calcinosis
The cause of the rare condition of tumoral calcinosis is not entirely understood. It is generally characterized by large, globular calcifications near joints. See also
Calcification
Calcinosis cutis
Dermatomyositis
Fahrs syndrome
Hyperphosphatemia
Primrose syndrome
Scleroderma

References
External links
 Media related to Calcinosis at Wikimedia Commons