Forecast origin shift
A feature value from a fixed time step before the forecast origin (when the forecast is made).
Example: A forecast origin shift of -2 uses the same value from 2 steps before the forecast origin for all the predicted values in the horizon.
Forecasted point shift (for multi-step forecasts)
A feature value from a time step that "slides" relative to each point in the forecast horizon.
Example: For a forecast from t+1 to t+2, a forecasted point shift of -7 uses the value at t-6 for the t+1 forecast and t-5 for the t+2 forecast.