Bytes C2 A0 in UTF-8 encode U+00A0 ɴᴏ-ʙʀᴇᴀᴋ sᴘᴀᴄᴇ, which can be used, for example, to display combining marks in isolation. It is
as a named HTML entity. It is almost the same as a U+0020 sᴘᴀᴄᴇ, except it prevents line breaks before or after it, and acts as a numerical separator for bidirectional layout.
The dot you see when you ask a text editor to show invisibles just happens to be what glyph the text editor chose to display spaces. It does not mean the character in question is U+00B7 ᴍɪᴅᴅʟᴇ ᴅᴏᴛ, which is definitely not invisible.
In code, if you have it as a unichar
, you can compare it to L'\x00A0'
.