[m12k]

One relatively easy to draw line is whether the abbreviation has other commonly used meanings. CNN has, while none of HTML, HTTP, HN or YC do.

[jerrre]

That really depends on the reader...

[Piskvorrr]

RMTG OSPG NNZA BZZZRAMT

https://trends.google.com/trends/explore?geo=US&q=%2Fm%2F0x2...