The AMSAT Keplerian format is essentially a labeled subset of the TLE Keplerian format. The AMSAT
format does not have the TLE's International Designator, Ephemeris Type, or its nddot/6 or Bstar drag terms. The decay rate is the ndot/2 drag term.
The AMSAT format has a single check sum computed by adding all the Keplerian element's digits, a "+1" for each negative (-) sign, and a "+2" for
each plus (+) sign. Note that the digits used for computing the check sum include all characters whether they are the orbital parameters themselves or the labels (such as the "2" in the decay units label).