What to do when 3rd party BSD/MIT software doesn't include a copyright notice or license text?

[verdy_p]

"Alistair Davidson" 
> My problem is that for our next version, we're planning to include a 
> couple of plugins which, although they're listed on their project page 
> as BSD or MIT licensed, they don't actually include any copyright 
> notice or license text in the original distribution, or anywhere else 
> that I can find. So the question is, what's the accepted practise in 
> these case? What do we need to do in order to comply with a license 
> that requires we reproduce something that doesn't seem to be present 
> in the original library?

Why not adding those copyright notices yourself as comments within the source files you are distributing, according 
to the terms you have found on the original site distributing these files? Such modification of source files would 
certainly not violate the licences, and notably those that allow people to distribute and modify the sources (BSD 
and MIT licences allow that).

Note that this would require you to date the statement, but you may not know the year of first publication, only the 
date of last modification for the files present in the distribution and the date at which you have consulted the 
website, which may change independantly later, and can be difficult to exhibit later if there's no certified archive 
of these sites.

For this reason, I can also suggest that you contact the authors of these plugins, so that they include these terms 
in their own distribution, if they really want that the terms of the licence they give to be effectively respected. 
Please ask them for confirmation about the effective terms that apply to their distribution, because it will be 
important to protect you, if they ever change their web site notice later or if they disappear on the web.