I've appreciated the tips posted on the newsgroup over the years and found something myself today that I thought I'd share.
I was working on a drawing today with a detail view were I wanted to show some hidden detail. Toggling on the hidden detail was too fussy, but I found I could 'convert enties' on the hidden lines I wanted and these stayed as hidden lines when the veiw was toggled back to hidden lines removed.
Very cool I thought... Could I have read about this somewhere?