Blue Mountain is a database of magazines: that is, it is a system that links information together. In order to link information about specific objects -- magazine titles, issues, and so on -- Blue Mountain must assign a unique identifier to each one. (This is a well-known feature of information science.) Doing so allows us -- programs and people -- to refer to these things unambiguously.

Blue Mountain adopts the Universal Resource Name conventions to compose unique identifiers for titles and issues, as well as for the metadata records (METS and MODS) used to encode information about them.

Blue Mountain assigns a URI to each magazine, magazine issue, METS record, and MODS record it maintains. We have developed a convention for composing these URIs. Formally, the convention can be expressed like this:

  <BMTNPREFIX>   ::=   "urn:PUL:bluemountain"
  <BMTNID>       ::=   "bmtn" <a-z><a-z><a-z>
  <DATESTRING>   ::=   CCYY-MM-DD | CCYY-MM | CCYY
  <ISSUEINDEX>   ::=   <0-9><0-9>
  <ISSUANCE>     ::=   <DATESTRING> "_" <ISSUEINDEX>
  <ISSUEID>       ::=   <BMTNID> "_" <ISSUANCE>

  <TITLEURI>     ::=   <BMTNPREFIX> ":" <BMTNID>
  <ISSUEURI>     ::=   <BMTNPREFIX> ":" <ISSUEID>
   
  <TITLEMETSURI> ::=   <BMTNPREFIX> ":td:" <BMTNID>
  <ISSUEMETSURI> ::=   <BMTNPREFIX> ":td:" <ISSUEID>

  <TITLEMODSURI> ::=   <BMTNPREFIX> ":dmd:" <BMTNID>
  <ISSUEMODSURI> ::=   <BMTNPREFIX> ":dmd:" <ISSUEID>

Let's take a more discursive look at this syntax.

The Blue Mountain Prefix is a fixed string that follows the functional requirements specified in RFC 1737