outgoing incoming Lightwave

hi!

I have a simple question about key-frames.someone knows the way to make
outgoing and incomig (used to splin einterpolation)value stored in key-envelope?

Key 0.95986253 0.5 1 0 0 0 0.2975094 0.17850564 0

incoming =0.2975094;
outgoing =0.17850564;

how lightwave make this values?