K-line
# K-line

K-line may refer to:

## Chemistry

* K-line (spectrometry), one of two features in spectroscopy:
   * Calcium K line, a Fraunhofer spectral line from ionised calcium
   * K-line (x-ray), an x-ray peak in astronomical spectrometry
* K line, a term used in Internal conversion electron spectroscopy

## Computing

* K-line (artificial intelligence) (Knowledge-line), a mental agent in artificial intelligence
* K-line (IRC), a server ban in IRC

## Finance

* Candlestick chart, or K-line, a style of financial chart used to describe price movements of a security, derivative, or currency

## Sports

* K line, the line marking the calculation point in ski jumping

## Transportation

* K (Broadway Brooklyn Local), earlier KK, discontinued in 1976
* K (Eighth Avenue Local), a defunct train service on the New York City Subway, which was known as the AA until 1985
* K Ingleside, a service of the San Francisco Municipal Railway sometimes called the K Line
* K Line (Los Angeles Metro), a light rail line in Los Angeles County, California
* K (Los Angeles Railway), defunct streetcar line in Los Angeles, California
* K Line, a Japanese shipping company
* K-Line, a model railway locomotive company
* K-Line bus operator in Yorkshire, England since rebranded as Tiger Blue
* K-Line, part of the ISO 9141 on-board diagnostics vehicle network interface standard
