The studs up or down on flowers thread got me to thinking... I have an itching desire to know why the "plant flower stem with three large leaves" is identified as"x8" in the various brick directories:
http://www.bricklink.com/catalogItem.asp?P=x8
It seems to be originally associated with the "girly" sets like Scala and Belville, which do have other parts starting with an "x" though that naming convention follows no rhyme or reason. For example, some Scala-specific parts begin with "scl" and others that are unique to that line are regular old numbers.
Can any LEGO historians shed light on what the logic was behind these catalog names and why they would have used the "x#" numbering system on just a handful of completely dissimilar elements?