[SR-Users] $ru vs. $fu as r/w pseudo variables

[Juha Heinanen]

Juha Heinanen writes:

> I looked at pv_core.c, and based on that these are header R/W variables:
> 
> $tu, $tU, $td, $tn, $fu, $fU, $fd, $fn

I updated the Wiki page accordingly.

-- Juha