Level Four Subdomains

creating subdomains

[Goto]

Hello,
I am new to this list.
I have three separate but related subdomain questions:

(1) Would someone on this list kindly advise about creating subdomains that resolve at level four
where "level4" is the fourth level subdomain?
ie:

[level4.level3.myname.com?...]
or:
[level3.myname.com...]

The point here is to create a level 4 subdomain that stands alone as a resolvable subset of the level 2 and level 3 dot-com. Level 4 is not a subdirectory of level 3.

(2) Which subdomain alternative methods (above)are best for DNS purposes and in the alternative for SEO?

(3) Is it true that it is feasible to create subdomains at any level left of the dot (.com) in dot-com, so long as the name(s) do not exceed 64 characters, including all the dots?

Thank you all very much for your kind assistance.
Goto

[mars9820]

DNS wise I think it is easier to keep all subs in front of the .com instead of making directories. In that case you can manage everything in BIND and direct to different webservers if needed.

Something like

http ://monitors.computers.mydomain.com

However personally I think it looks spammy to work with these kind of structures. On the other hand I see quite a lot of companies doing this and they are quite successful on the keywords in the subdomains.