This is a strange issue – one that I’ve never noticed before. A verification tag on one of my sites was not being recognised, so I took a closer look at the meta tag and I noticed the double-quotes were missing from the name and content attributes.
Then I spotted a few more tags, some with double quotes missing from both and others where it was missing from just the first attribute.
I thought this was confined to the <head> but can see the same occuring in the <body>.
I’ve checked our other sites and their page source looks as I would expect (double quotes surrounding the arguments of each tag), they’re also on the same server using the same configuration files.
The site where I am noticing this – skiddmark.com – we’ve been running now since 2007, and I’m not noticing any functional consequences – it continues to work fine, but I’ve really no idea why the front-end source code no longer contains these double-quotes.
Anyone experienced something similar?
For anyone who is interested in the answer to my question, the cause of my missing quotation marks was due to Google’s modPagespeed which I’ve been running for several years now, but which I upgraded to the latest development version last month.
I will get in touch with the modPagespeed team and report it as a bug and see if we can find a solution.
Thanks for everybody’s contribution and comments – as I said, I wasn’t looking for ‘advice’ or a ready-made ‘solution’, just a discussion which would help free up my imagination and help me think laterally..