What is the Purpose of This Rubber Strip

[KFH]

While cleaning up the front guards for painting I came across a U shaped rubber strip on the lower return at the rear of the front guard.  It is around 5" long and starts at the bead near the bottom of the guard and only on the RH one.  The guards appear to not having been removed since manufacture.  What is the purpose of this rubber strip?

Keith

[zulu]

To promote & encourage rust 
Ken (mcl1959) would know, there was a thread about it ages ago, maybe an anti rattle or weatherstrip.
Looks like a fairly healthy lower guard there

Cheers, Gary

[mcl1959]

Anti squeak / anti rattle - also stops water splashed up from the tyre coming out through the lower guard area.

Ken

[KFH]

Thanks Gary and Ken for the information.  That was my thoughts.  Under the guards I intend to give the vulnerable areas for rust a couple of coats of POR15.  This should also give rust protection under the rubber strip.  Under the headlight peaks are already done.

Keith