Annoyingly often in physics, some textbooks and articles would use definitions for certain quatities with the opposite sign from other textbook/articles. This lack of standardization is a frequent source of confusion, misunderstandings and even outright errors. A choice of signs in the definition is called a

**sign convention**. Sometimes, this term is used more sloppily to include factors of i and 2&pi.

A noncomprehensive list of sign conventions:

- In relativity, the metric signature could either be +--- or -+++.
- The choice of in the Dirac equation.
- The sign of the Faraday 2-form in gauge theories.
- The sign of work in the first law of thermodynamics.

**Warning**: Since this encyclopedia is written by hundreds of different mathematicians/physicists, there is absolutely no guarantee of consistency in sign conventions here. Proceed at your own peril.

*This article is a stub. You can help Wikipedia by fixing it.*