The ANALOG:DESCRIPTIONS parameter is a character data array that usually consists of a short description of each analog channel referenced by the ANALOG:LABELS parameter.  There should always be a one to one relationship between the number of LABELS and the number of DESCRIPTIONS.  Although it is not essential, there should generally be a one to one relationship between the number of LABELS and the number of DESCRIPTIONS.  By convention, these entries usually contain upper and lower case ASCII characters and are typically 32 characters in length but may be up to 127 characters long in a signed C3D file or 255 characters in an unsigned C3D file.

This parameter exists to provide documentation about each of the individual analog channels.  The ANALOG:LABELS parameter generally stores a short abbreviation of each analog channel name such as 1FX, EM05 etc.  Each of the channels referenced by these LABELS generally has a longer ANALOG:DESCRIPTIONS such as Force Plate One – Fx channel and Left Extensor Hallucis Longus etc.

Note that, like the POINTS:DESCRIPTIONS, the ANALOG:DESCRIPTIONS are provided simply as a means of providing a human readable description or documentation of the analog channel.  Software applications that need to access individual analog channels should access each channel by use of the ANALOG:LABEL, not the ANALOG:DESCRIPTION parameter.