Coulomb force over Rindler horizon

[sweet springs]

No, their Rindler horizon is the two null lines X=TX=TX = T (the future horizon) and X=−TX=−TX = -T (the past horizon).

I would like do some clarification.
https://en.wikipedia.org/wiki/File:Rindler_chart.svg says horizons are half line starting from origin of the IFR. Rindler coordinate has nothing to do with other half part.

In the sense that

Events in #2 and #3 can effect on events in #3 Rindler area.
Events in #1 and #4 can not effect on events in #3 Rindler area.

not half lines but full lines of X=T,-T seem to have meanings in IFR. Is there definition on half or full ?

 

[PeterDonis]

I would like do some clarification.

Wikipedia is not a valid source.

Is there definition half or full ?

Both meanings could be used; you have to determine which is intended from context.