AH> the message arrives with the following SEEN-BY line

AH> SEEN-BY 1:2/9 5 6 1/0

that's an invalid seenby line... seenby's are sorted...

AH> (1:2/9's downlinks are 1:2/5 and 1:2/6)
AH> (1:1/0's downlinks are 1:1/5 and 1:1/6 and 1:2/0 and 1:2/4)

AH> should 1:1/0 add only at the end of the SEEN-BY line:
AH>    SEEN-BY 1:2/9 5 6 1/0 5 6 2/0 4
AH> or can it insert half-way:
AH>    SEEN-BY 1:2/9 5 6 0 4 1/0 5 6

AH> Inserting half-way makes the SEEN-BY shorter, and allowing to insert
AH> half-way might make a large difference with long SEEN-BY lines (and
AH> funny routing). 

see above... both the above are invalid... they should be like this...

ie: SEEN-BY 1:1/0 5 6 2/0 4 5 6 9

)\/(ark