Don’t let me add invalid characters in a field

I’m tired of things letting me use a character, then later on telling me it’s invalid. Today it was Microsoft, but many companies do this. I needed to search for something in a mailbox I was going to name the search “Search Term” Search to make it obvious to me what I was searching for (I was searching for several terms so there are multiple searches). I then went through several more pages for exact search terms, and then I was told:

Now there isn’t really any good reason why you can’t use specific characters. It’s not like using escape characters to get around this is a new thing. There is a whole Wikipedia page about it and the linked page (from the wayback machine as the page is down) says 1956. If you don’t know what an escape character is, it’s a way of reusing characters. For example a common one would be a tab character – how do you find one in a text editor if the ‘find’ field only accepts text. Let me introduce you to the \ character. \t is a tab character in a lot of editors (here is a screenshot from Notepad++ one of my favourite editors)

Note the extended options

\t there is the tab as mentioned earlier, and \n and \r are new lines. Characters you can’t just type.

OK \n is a new line \r is carriage return but depending on your operating system a new line might be just \n, or \r, or \n\r and I really don’t want to go into all of this here

In short, if you can’t accept certain characters (which you should, but let’s say you can’t) stop me on page 1. Don’t wait until page 12 and then make me skip back 11 pages to redo it, and make me have to then re-read those pages!