1800 characters might seem like an arbitrary number, but it helps us ensure that we’re creating a consistent product and puts all the contributors on an even playing field. We think 1800 characters is a reasonable amount of space to communicate your feelings clearly and have sometimes found that giving a limit actually results in words that are better-written, to the point, fat-trimmed, and ultimately much easier for the recipient to digest. However, it’s just a suggestion and not a hard limit, so you are welcome to write more, if you like.