Why do some websites use copyright protection instead of "copy "?©? -

For example, Baidu, zhihu such as Baidu, zhihu reply content: In the case that the coding statement of the page and the encoding recognition of the client browser are reliable (such as the declaration of the UTF-8, for modern browsers), there is no need to use character reference (including character entity reference and numeric character reference) for characters that have a clear appearance and do not have to be escaped ). If the appearance of special spaces and various invisible characters is unknown, use character reference to facilitate code maintenance.
Of course, sometimes it is inconvenient to search for and enter special characters, so using character reference is also convenient to input, which is no good.
In addition, if numeric character reference is required, we recommend that you use the hexadecimal format starting with & # x, which is consistent with the Unicode scalar value and is more convenient. I just read it.©Baidu homepage is©W3C is©;
Currently, the only difference is that the character length is different.©; It can be correctly displayed under different encoding types, such as gbk or UTF-8.
In addition, an answer on stackoverflow (does it seem unnecessary to use HTML character entities ?) :

You don't generally need to use HTML character entities if your editor supports Unicode. Entities can be useful when:

• Your keyboard does not support the character you need to type. For example, please keyboards do not have em-dash or the copyright symbol.
• Your editor does not support Unicode (very common some years ago, but probably not today ).
• You want to make it explicit in the source what is happening. For example, the code is clearer than the corresponding white space character.
• You need to escape HTML special characters like <, &, or ".

'©'Has 6 Characters and ''has only 1 character. Nice looking