looking for an ordinal notation paper

[Hendrik Boom]

Several years ago, maybe even several decades, I read a posting on this 
mailing list presenting an ordinal notation that I have not been able to 
find again.

I remember that the notation used horizontal extended parentheses, rather 
resembling ties and slurs in musical notation, and that the nesting 
patterns of these parentheses contributed to the meaning of the notation.

Can anyone provide a link to the posting or the associated paper(s)?

-- Hendrik Boom