'Obviously you want to change to formatting of the plugin messages...'
- yes, but I've HAD to detail the mark-up in order to hang my styles off it. It's annoying for front-end developers, like myself, who use WordPress plug-ins, no less average users with basic CSS knowledge, to have to go into PHP to find and amend (sloppy) mark-up.
'...but the code you've posted will put the message into italics for all users'
- true, but remember the primary importance of HTML is meaning, not styling.
Not only does
<em> provide the correct meaning (emphasis) to any validation errors/flags/ or notifications IMO, it also has the added benefit of providing a more granular marker to hang styles off.
I would consider any of the following 'correct' alternatives, but some marker would be better than nothing!:
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Thanks for your email Matt. I hope this is a suitable explanation.