To build on Mary Jane's point, I think that the examples are useful but 
that there are also some serious omissions in that section of the NACO 
manual.   There's no mention of $u at all and there isn't even one 
example showing a URL being used in a 670.  In fact, the formula given 
there for including URLs is contributing to the problem because it shows 
the URL embedded in $a with other information:

Internet, URL: [URL address],[date of search] $b ([information])
Since we're all supposed to be following the NACO manual, it's not 
surprising to me that we are not finding uniform practice.  If there 
were an example to guide usage, I think we would all gratefully follow it.

Celine Noel
UNC-Chapel Hill

Mary Jane Cuneo wrote:

> Wayne, I do the same thing.  I think of it as the equivalent of citing 
> "t.p." or "p. [whatever]" in 670 when the source is a book.  There is 
> an example in the NACO Participants' Manual. (Section I: New Authority 
> Records/ 670 Field / XV.Citing Internet Resources, third example:  |b 
> contact us page -- an especially nice example for the informal 
> internet-flavored language, which is indeed what we usually end up 
> citing.)
> Mary Jane Cuneo
> Serials cataloging and NACO
> Fine Arts Library
> Harvard University
> Wayne Richter wrote:
>> <snip> In citing these in 670s I usually use "history
>> page" or "history pages" following the name of the web site, and
>> followed by the date viewed. I rarely find the information I need on the
>> home page so I wonder if this is common and recommended practice (i.e.
>> citing particular areas of a web site)?
>> Thank you.
>> Wayne Richter
>> Asian Materials Specialist/PCC Liaison
>> The Libraries
>> Western Washington University
>> Bellingham, WA 98225-9103