Escaping left and right brackets in forum posts

[ledtester]

Just sharing a method I learned to "escape" left and right square brackets in BBcode (the markup language used here on the forum) - that is, to insert BBcode tags into your post without having them interpreted as tags.

Most of the time you can use the [code] tag, e.g.:

To insert a link use the url tag, for example:

Code: [Select]

[url=https://cnn.com]This is CNN[/url]
will produce the link: This is CNN

But what if you want to show how to use the [code] tag? Using:

[code]
To format code in a post, use a [code] ... [/code] block.
[/code]

doesn't work because code blocks do not nest - the first end code tag will terminate the outer code block.

Or what if you want the tags to appear inline, e.g.

using [s]some text[/s] will make "some text" appear with a line through it, e.g. some text

The trick is to use a style tag to break-up the tag you want to insert literally, e.g. to insert [TAG] use:

Code: [Select]

[color=black][TAG[/color][color=black]][/color]

Besides the [color] tag other style tags will also work for this purpose, e.g. [b], [i], [u], [s], [tt], [font], [size]. Of course, whatever style tag you use will affect the enclosed text.

[magic]

Interesting question.

Not sure if there is any "official" solution, but I came up with a simpler version of your hack:

Code: [Select]

[[b][/b]code][code]

[tooki]

Interesting question.

Not sure if there is any "official" solution, but I came up with a simpler version of your hack:

Code: [Select]

[[b][/b]code][code]

Yep. I also use this exact trick to break up unwanted smileys, like 8) (which otherwise becomes — this has to be the most poorly thought-out smiley shortcut ever conceived).

[Brumby]

Yeah, I've used this trick for years, usually with the colour - but you don't have to do it to the trailing bracket

[color=black][TAG[/color]]  =  [TAG]

[tom66]

You can also use similar characters, though they won't copy-and-paste correctly.

For instance, this is an example using с (Cyrillic 'Es'), which is not c (Latin 'c').

[сode]Testing[/сode]

This has security implications for creating similar-appearing text that has different binary signatures, think web URLs.  Imagine:  paypal.com vs рayрal.com.  These are different, but only in Unicode land.  Thankfully, there are steps taken to reduce the chance of this being a practical attack in the real world.