Documentation

Suffixes containing special characters

You might see (or inherit responsibility for) older DOIs which contain other characters, and require special treatment in a URL:

• Encode hash or pound sign # as %23
• Do not encode left bracket (or less than) < as < and right bracket (or greater than) > as > when resolving DOIs or retrieving metadata from our REST API to retrieve the metadata (see below)
• Do not encode forward slash / when resolving DOIs or retrieving metadata from our REST API

For example, use the following when resolving DOIs with special characters:

https://doi.org/10.1002/(SICI)1521-3951(199911)216:1<135::AID-PSSB135>3.0.CO;2-%23

instead of:

https://doi.org/10.1002/(SICI)1521-3951(199911)216:1<135::AID-PSSB135>3.0.CO;2-#

And, to retrieve the metadata in our REST API, using those same DOI examples use:

https://api.crossref.org/works/10.1002/(SICI)1521-3951(199911)216:1%3C135::AID-PSSB135%3E3.0.CO;2-%23

instead of:

https://api.crossref.org/works/10.1002/(SICI)1521-3951(199911)216:1<135::AID-PSSB135>3.0.CO;2-#