I was wondering why some Esperantists use the x system (it isn't in the Esperanto alphabet) instead of h (which is in the Esperanto alphabet). Should not it be promoted to h, regularized, or something like that?
Two arguments I have encountered for preferring "x" to "h":
Because it is not an existing letter in the Esperanto alphabet, automated conversion is possible, e.g. sx could be unambiguously converted to ŝ. By contrast, even if combinations like -sh- are rare, they could occur in compound words e.g. dishaki, so sh cannot be reliably converted to ŝ (similarly senchava, flughaveno, etc).
Because it is so near the end of the alphabet, it is almost always the case that a naive lexical sorting will achieve correct alphabetical order. So for example, a naive sorting would put sxi after sorto (which would be correct, because ŝi comes after sorto), but would put shi before sorto. This only fails when a letter to which an accent could be applied is followed by z; for example a naive sort would misorder uxato (ŭato) and uzi, but such occurrences are very rare.
People tend to prefer the x-system exactly because it isn’t a letter in the Esperanto alphabet, so there is no risk of confusion. For example if you see the word flughaveno you might first ask yourself ‘what is a fluĝo?’ before recognising the word. With the X-system there is no such ambiguity.
These days the hats are pretty widely supported in browsers and most software, and it’s usually not too difficult to install some software to help type them, so both systems are less and less common.
I personally prefer the more natural h (ch, sh) and such a notation was proposed as alternative for Esperanto letters.
In the newer times the alternative with x was introduced with as argument: automatic translation. As
chashundo was ambiguous
chas-hundo. Try reta-vortaro.de with x's.
It is a subcultural phenomenon I think. Like accented characters are very dear to the language users. German without umlauts, a French café without accent droite, Spanish ñ. Even English borrowing façade.
Both are legal and understood. So use h with hyphens (chas-hundo) if it pleases. Meanwhile I am content to use x too.
By the way for smartphones one can install Esperanto support for the letters.
The x-system is a reform attempt to Esperanto. Yes, it also should be changed to the h-system, because the cases in which the x-system is used are often the same cases that the h-system can be used, such as in urls.
An example is in url paths:
In the h-system, the breve is removed so the ´ŭ´ is stored as ´u´. The x-system reformists think this transformation would cause problems with ambiguity, which is why they formed it. However this thought is not true; ´ŭ´ and ´u´ are distinguishable by letter name: ŭo ≠ u.
For reference, here is the alphabet of Esperanto from the ekzercaro in the Fundamento de Esperanto:
So one can store each Esperanto letter by their name in the h-system, to fully capture and save Esperanto text by the h-system. For example: "aŭtismulo" would be stored in the h-system as [a uo to i so mo u lo o].