Accessible links in PDFs

To the average user, URLs in a PDF are clickable in Acrobat or Adobe Reader only if:

• They begin with http:// and/or www. Something like bbc.co.uk won’t work (although it will in Preview, the PDF and image viewer built in to the Mac OS.)
• The ‘Create links from URLs’ preference is on.
• The PDF has been made a ‘tagged PDF’ when it was created. Distiller/Creative Suite PDF settings include this option, and it’s on by default for most settings, but not the press quality ones.

Even with all these criteria satisfied, URLs may not be accessible to screen readers. Acrobat’s  help says:

Unlike the other methods for creating links in a tagged PDF (by using the Links tool or the Create From URLs In Document command), the Create Link command adds all three tags that screen readers require in order to recognize a link.

Manually creating links is rather time-consuming for a large document, but appears to be the only way. The Create Link command is available in Acrobat by selecting the URL then right-clicking.