Where does this style work?

It works wherever plain text is accepted — bios, usernames and comments — because the letters are real Unicode characters, not a font.

Can I copy it together with other words?

Yes — copy the whole output and paste it next to plain text; every letter stands alone.

Heavy sans — usernames and titles

Sans bold is the heavy sans-serif alphabet (𝗔-𝘇, 𝟬-𝟵) — the modern-bold look for usernames and titles.

𝗬𝗼𝘂𝗿 𝘁𝗲𝘅𝘁 𝗵𝗲𝗿𝗲