Plugging an RJ11 into an RJ45 socket can damage some RJ45 sockets
by bending Pins 1 & 8.  RJ45 sockets are on some very expensive
computer equipment, so I would claim that a design goal of RJ45
connectors would (or should be) to avoid this problem.

This somewhat supports my opinion, but I can't find the evidence.
http://www.rj45info.com
http://www.engineeringtalk.com/news/mom/mom102.html
http://www.ultrajax.com/FAQ2-ultra.htm

what's the question?

Hi, dibert-ga:

I think it was actually a design goal that the smaller RJ11 connector
could be plugged into an RJ45 socket, in the center position (equally
spaced on both sides).  Perhaps what you are saying is that RJ45
sockets should be redesigned so that this centering/equal spacing is
"enforced" by the design?

Unfortunately, of course, there's a lot of existing network cabling
installed out there.  If the costs of upgrading existing installations
have to be considered, I think the occasional insult to an RJ45 socket
would seem small potatoes.  But your comment is a good "lesson" to
keep in mind for future "compatibility" engineering.

regards, mathtalk-ga

According to the EIA/TIA standards you MUST be able to plug in a
"RJ11" into a "RJ45".  "RJ11" is really a 6p4c and and "RJ45" is a
8p8c.  6 pin 4 connector and a 8 pin 8 connector.