It can be many Zero-Width Space, or a few Hair-Width Space.

You never know, when you don’t know CSS and try to align your pixels with spaces. Some programers should start a trend where 1 tab = 3 hairline-width spaces (smaller than 1 char width).

Next up: The <half-br/> tag.

You laugh but my typewriter could do half-br 40 years ago. Was used for typing super/subscript.