Mursten

[N. W. Perry]

one brick from the mursten/system border has some open questions for me:
700b.dat  https://library.ldraw.org/parts/49695
u8010d.dat https://library.ldraw.org/parts/26968
bottom studs indicate system (logo on top studs), which brick is correct?
I have some of these bricks, the only one without stud logo is the one with the small triangular supports.
Even the ones with the low cross have stud logos.
u8010c.dat https://library.ldraw.org/parts/26967

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…