For sometime I have been collecting digital object identifiers (DOIs) in my BibTeX entries, as described in this blog post. When I use my own BST file to format the references BibTeX creates hyperlinks to the published source via the DOI. If I use the the SIAM BST file the DOI is instead displayed as part of the reference.

The Crossref organization (which provides DOIs) has recently issued revised guidelines on the display of DOIs. Up until now, DOIs have typically been displayed as, for example, 10.1137/130920137, and linked to as http://dx.doi.org/10.1137/16M1057577. The new guidelines say that the link should be https://doi.org/10.1137/16M1057577 and that it should always be displayed in this form, as a full URL. Note that the “dx” part of the URL has gone, and “https” has replaced “http”.

The main reason for the change is that the pure DOI on its own is not much use, as it can’t be clicked on or pasted into a browser address bar without first adding the https://doi.org/ prefix. Additionally, https provides more secure browsing than http, and Google gives a small ranking boost to sites that use https.

Crossmark states that the old http://dx.doi.org/10.1137/16M1057577 form of URL will continue to work forever.

I have updated my BST file myplain2-doi.bst in this GitHub repository, which contains a BibTeX bibliography for all my outputs, so that it produces links in the required form.

SIAM has updated the BST file in its macro packages to implement the new guidelines.