html - mailto: link equivalent for phone calls?

Is there any way using html and/or JS to link an image so that it makes a phone call. Similar to the mailto: links. This would just make life a lot easier if this was possible. Say if a person had skype, could a button then open skype for them and call a number?

Thanks in advance

Answer

like this:

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you can look also on this article

add-telephone-number-links-with-html