Keywords common to all templates

• TPL.ID contains an unique identifier describing the template which was used to produce the data. Frame selection in the pipeline is mostly based on this keyword value.
• DPR.CATG Data Product category (SCIENCE, CALIB, ...).
• DPR.TYPE Data Product type (OBJECT, SKY, ...).
• DPR.TECH Data Product acquisition technique (e.g. IMAGE, SPECTRUM).
• TPL.NEXP Number of scheduled exposures within the template. ^3.1
• TPL.EXPNO Exposure number within template.

A template may produce several different frame types. Frames are discriminated by the value of the DPR keywords: DPR.CATG, DPR.TYPE, and DPR.TECH take different values depending on the observed frame type.