(Yesterday, 16:57)N. W. Perry Wrote: This also raises the question of when/where the term "Mursten" should apply for library purposes. While "mursten" is simply Danish for "brick", it usually denotes the period from 1953–1957 or so, when boxes were labeled "LEGO Mursten". We would usually also include the first Automatic Binding Bricks from 1949–1952 in this category, even though it predates the Mursten era from the historians' point of view.
Perhaps more importantly, should the term be used in any part where bottom tubes exist? The introduction of tubes in 1958 pretty much conclusively marks the end of any early historical period for which a qualifying term like "Mursten" seems useful. But what does the LDraw user actually expect from seeing this term? Is it better to use it too much, at the risk of being inaccurate? Is it OK as a keyword, even where it mightn't be as a category? And so forth, and so on…
Although the term LEGO System was introduced in 1955 and appears alongside Mursten on set packaging, I associate System with the "stud and tube" innovation patented in 1958.
I accept the historical inaccuracy when including Automatic Building Bricks in the Mursten category due to the slot similarity. For simplicity, I would also include the "Plastic Building Bricks" 1949-1955 if not for any other reason than that 'Automatic Building Bricks' and 'Plastic Building Bricks' are too long.
I would exclude Jumbo and Kiddicraft bricks from the Mursten category. The point being that not all bricks produced before "stud and tube" need be Mursten.