Until I deleted it this afternoon, the following tag appeared on one of the entries in the File Exchange: “can u plz send me the entire project report on my email address”. That’s all one tag. I can’t remember which file I deleted it from, but it hardly matters. It is not, we might say, a very helpful tag.

Tags, as you probably know, are meant to be words or short word phrases that describe an item. We use tags on the File Exchange, Answers, and Cody. They can be very helpful when you want to move around in a set of related content. For instance, two people might give similar files very different names. One might be called “Solar Position” and the other one “Sun Tracking”. Based on only these titles, no single search will find both files, even though somebody interested in one of these is probably interested in both. But now suppose I come along and add the tags astronomy and solar to both of them. I’ve added value to our little community of MATLAB-based sun enthusiasts, because now one search WILL find both files (since tags are included in the search index).

That’s the big idea behind tags: extra words to make search work better. And you can always click on the tag directly to find all other items with the same tag. One of the important things about tags is that anyone, not just the author, can add them.

But now I need to tell you about Souza’s Law.

Souza’s Law, named for Randy Souza, the MathWorks developer who first pointed it out to me, states that any text area will eventually be used for posing technical support questions. That is, if you can type into it, one day somebody will put in a question about how to use the “print -depsc” command option for a resolution of 300 DPI. Even if the text box was labeled “Surname.”

As a concrete example of Souza’s Law, here is a list of actual File Exchange tags that I cleaned up recently. They all start with “can”.

It’s our job here at MATLAB Central to make sure the site is easy to use, so we need to think about ways to make it clearer what tagging is and how to use it effectively. But I just couldn’t resist showing you this amazing demonstration of Souza’s Law. Now that you’ve heard about it, you’ll start seeing it all over the place.

Also, as a general piece of advice, if you want somebody on the internet to help you, don’t start with the words “can u plz”.