(An exception to this rule is the Super League, which uses static squad numbering.) In rugby union:
One of the two starting locks wears the jersey number 4. In the standard bonus points system, a point is awarded in the league standings to a team that scores at least 4 tries in a match, regardless of the match result. In other fields
The phrase "four-letter word" is used to describe many swear words in the English language. Four is the only number whose name in English has the same number of letters as its value. Four (四, formal writing: 肆, pinyin sì) is considered an unlucky number in Chinese, Korean, Vietnamese and Japanese cultures mostly in Eastern Asia because it sounds like the word "death" (死, pinyin sǐ). To avoid complaints from people with tetraphobia, many numbered product lines skip the "four": e.g. Nokia cell phones (there was no series beginning with a 4 until the Nokia 4.2), Palm PDAs, etc. Some buildings skip floor 4 or replace the number with the letter "F", particularly in heavily Asian areas. See tetraphobia and Numbers in Chinese culture. In Pythagorean numerology (a pseudocience) the number 4 represents security and stability. The number of characters in a canonical four-character idiom. In the NATO phonetic alphabet, the digit 4 is called "fower". In astrology, Cancer is the 4th astrological sign of the Zodiac. In Tarot, The Emperor is the fourth trump or Major Arcana card.
Fat necrosis is a form of necrosis characterized by the action upon fat by digestive enzymes.In fat necrosis the enzyme lipase releases fatty acids from triglycerides. The fatty acids then complex with calcium to form soaps. These soaps appear as white chalky deposits.It is usually associated with trauma of the pancreas or acute pancreatitis. It can also occur in the breast, the salivary glands and neonates after a traumatic delivery. Signs and symptoms
Signs and symptoms of fat necrosis are presented below:

masses that seem to be irregular beneath the skin, by touch these should feel smooth and rounded. tenderness in areas with masses
skin tethering
dimpling
nipple retraction

Causes
Fat necrosis occurs primarily in the breast and pancreas. Breast lesions are mostly caused by adipose tissue trauma or post-surgical complications (e.g. hypoxia). Pancreatic lesions arise as a result of the pathological release of pancreatic enzymes which digest surrounding adipose tissue. Fat necrosis is also a feature of some diseases that cause inflammation of subcutaneous fat (panniculitis). Examples of causes include but are not limited to:

Breast trauma (e.g. seat belt injury from a car accident)
Breast surgery
Fine needle aspiration biopsy and cytology (FNAB, FNAC)
Radiotherapy
Lumpectomy
Reduction mammoplasty
Breast reconstruction
Pancreatic disease
Acute pancreatitis
Pancreatic cancer
Pancreatic injury
Some forms of panniculitis
Subcutaneous fat necrosis of the newborn
Weber–Christian disease
Polyarteritis nodosa

Pathophysiology
Fat necrosis is the pattern of damage associated with the destruction of adipose tissue by trauma, hypoxia, or lipase digestion (e.g. pancreatitis). In the classic case of fat necrosis in severe acute pancreatitis, the necrosis arises because adipocytes in the peritoneum are broken and digested by inappropriately activated pancreatic enzymes.