Wikipedia:Manual of Style/Character Table 1

Avoid	Instead use	Note
Characters to avoid \| v
`…` (`…`)	`...` (i.e. 3 periods)	See MOS:ELLIPSIS.
Unicode fractions like: `¼` `½` `¾` `&frasl;`	{{frac}}, {{sfrac}}	See MOS:FRAC.
Unicode subscripts and superscripts like: `¹` `²` `³` `ª` `º`	`<sup></sup>` `<sub></sub>`	See WP:SUPSCRIPT.
`µ` (`µ`)	`μ` (`μ`)	See MOS:NUM#Specific units
Ligatures like: `Æ` `æ` `Œ` `œ`	Separate letters (`AEaeOEoe`)	Generally avoid except in proper names and text in languages in which they are standard. See MOS:LIGATURES.
`∑` (`∑`) `∏` (`∏`) `―` (`&horbar;`)	`Σ` (`Σ`) `Π` (`Π`) `—` (`—`)
`‘` (`‘`) `’` (`’`) `‚` (`&sbquo;`) `“` (`“`) `”` (`”`) `„` (`&bdquo;`) `´` (`´`) `′` (`′`) `″` (`″`) ` (```)	Straight quotes (`"` and `'`)	These characters are used in math notation; elsewhere use straight quotes. See MOS:QUOTEMARKS.
`&ensp;` `&emsp;` ` ` `&hairsp;`	Normal space	Whitespace other than the non-breaking ` ` and regular space should be avoided in prose. ` ` and `&hairsp;` are sometimes used for precision positioning in templates, but should be avoided in prose.^[why?]
`&zwj;` `&zwnj;`	Used in certain foreign-language words, see zero-width joiner/zero-width non-joiner. Should be avoided elsewhere.
`·` (`·`) `•` (`•`) `⋅` (`⋅`) should be avoided in creating vertical lists.	For vertical lists, wiki markup using `*` should be used instead. See HELP:LIST#List basics