Mind Your Language deals with a wide range of linguistic screw-ups, but there is only one candidate for the most common mistake in current written English. Step forward, it's being used when its is needed.
The photo above shows the caption on a bottle of wine I consumed on a recent Qantas flight. As you can see, the florid description of the wine on the reverse label includes the phrase "It's maritime climate produces". This is wrong. It should read "Its maritime climate produces". The incorrect version would expand to "It is maritime climate produces", which makes no sense whatsoever. This can't really be blamed on auto-correct. It can potentially be blamed on laziness.
This wine has been bottled specifically for Qantas, and I imagine there was an approval process for the design of the label. Evidently, checking the spelling wasn't deemed an important part of that process. Airlines of all organisations should know that small details are important. Accuracy matters. If you can't tell when to use its or it's, see our detailed guide to using apostrophes properly.
Lifehacker's Mind Your Language column offers bossy advice on improving your writing.