Beginning with EMLS 2.2, we have employed what is known as a Persistent Uniform Resource Locator (PURL). A PURL is a URL which points not directly to a location but, rather, points to a service which will redirect a WWW browser to the location being sought. More information about PURLs can be found on the Online Computer Library Center (OCLC) PURL page, at <URL: http://purl.oclc.org/>.

This action reflects thought on a number of concerns, most notably the strong desire that the pages of EMLS have a stable address (if not exact location) for purposes of access, linking, citation, and so forth. This desire, perhaps idealistic when one considers the nature of the medium in which EMLS publishes, is challenged by what is a very pragmatic concern: in the near future, the local machine which hosts our server will be moving and, consequently, EMLS materials will move along with it. Adopting a PURL some time before the move assists in making the transition from one machine to another, and one URL to another, slightly less awkward than it would be otherwise; in practical terms, it allows considerable interim period for the many direct links to our pages, and for the personal bookmarks of our regular readers and users, to be updated. As well -- and in consideration of the flux which, sadly, can characterize aspects of publication in the electronic medium -- it ensures that future moves will take place seamlessly.

PURL addresses for our three sites are as follows:

• EMLS (Vancouver), <URL: http://purl.oclc.org/emls/emlshome.html>,
• EMLS Mirror Site (Oxford), <URL: http://purl.oclc.org/emls/UK/emlshome.html>,
• Interactive EMLS (Vancouver), <URL: http://purl.oclc.org/emls/iemls/iemlshom.html>.

The structural organization of our pages will remain unaltered, and the URL for our archive at the National Library of Canada, <URL: http://www.nlc-bnc.ca/eppp-archive/emls/>, will not be altered to PURL format.

To alter links and bookmarks to reflect our PURL, we suggest the following:

• For links and bookmarks to materials at our Vancouver EMLS site: convert the site prefix of our URL, which currently reads "http://www.library.ubc.ca/emls/", to "http://purl.oclc.org/emls/".
• For links and bookmarks to materials at our Oxford EMLS mirror site: convert the site prefix of our URL, which currently reads "http://users.ox.ac.uk/~emls/", to "http://purl.oclc.org/emls/UK/".
• For links and bookmarks to materials at the Interactive EMLS site: convert the site prefix of our URL, which currently reads "http://edziza.arts.ubc.ca/english/iemls/", to "http://purl.oclc.org/emls/iemls/".

We apologize for any inconvenience this may cause, but hope that our readers will agree that, at this time, a resolution service for our URL such as that offered by OCLC will ensure that future machine relocations will be able to proceed with no interruption of service.

R.G.S.

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