Jonathan makes an interesting point,
"In the last generation or so there's been a considerable shift toward higher standards in accurately recording the provenance of items, attribution of ideas/script work to those who used the items and much interest in historical precedence as regards the development of ideas, scripts, themes and some artistic/aesthetic trends over time."
If you flick through an old book, say mid 1800s to early 1900s, all of the tricks are headed under generic titles, rarely with any idea of the origins of that particular effect - whereas now, it's considered very bad form not to at least reference anyone whose routine you've developed or asked permission if you're publishing it outright.
I think older books for a general audience wanted to be more instructive and encyclopedic to provide 'a complete course in magic', whereas specific publications for magicians naturally assume a degree of interest and experience so, I suppose the origins of the material is more interesting and important to the specialised reader - as well as to the economy of producing these specialised books.
Interestingly though, it's the same today. If you go into a general bookstore and look under their 'sports and games' section for a magic book, they feature similar stuff to the old books with little elaboration on the origins of the material - probably because this isn't of interest or relevance to the general reader.
I know with people here who make a living out of publishing original material, the consensus is probably that the current caution surrounding provenance is wholly justified in an internet age where things can be and are ripped off. Does anyone have an opinion to the contrary? (playing devil's advocate) Are we making mountains out of molehills in a world where intellectual property is increasingly not worth the paper it's printed on?
I personally like to hear about who came up with what because if I happen upon a book by that same person, I'll have a good idea as to whether I'll enjoy it. What do you think the groundrules are on referencing and publishing variations? Just how original should a routine be to justify publication?
(Just trying to stir things up abit ;)