The first one: <abbr> or <acronym>
These two logos are the same thing, mainly used in some English abbreviations. When you move the mouse up, you will find a small prompt to prompt the full name of the abbreviation. Here is an example:
<ABBR title=HyperText Markup Language>HTML </ABBR>
<ABBR title=Institute of Electrical and Electronics Engineers> IEEE </ABBR>
<ABBR title=Read the Fucking Source Code>RTFSC</ABBR>
The second one: <q>This logo mainly adds double quotes to the quoted text, which seems to be meaningless. The official said it is for convenience, but I always feel that this logo is not as convenient as entering double quotes directly. It seems that nothing is true. Could this logo be only seen under Firefox, and IE does not support it. Here is an example: This is an introduction <Q>This is an introduction</Q> This is an introduction
Third, <bdo>This logo is very interesting, and it can reverse all the word orders from left to right. For example: May I help you sir? If this logo is added, it will look like this: May I help you sir? What can I help you sir? <BDO dir=rtl>May I help you sir ?</BDO> <BDO dir=rtl>What can I do to serve you? </BDO> May I help you sir?What can I do to serve you?
Fourth, <del> add a strikethrough to your string. For example: This is a deleted text. <DEL>This is a delete text</DEL> This is a delete text
The fifth and sixth ones, the two are subscripts and superscripts. Here is an example: This is a subscript, this is a superscript. This is a <SUB>subscript</SUB>, this is a <SUP>superscript</SUP>