What is the most standard subnet length on internet

[patrick at ianai.net (Patrick W. Gilmore)]

Even if a longer prefix like a /24 is announced, chances of people
accepting it is slim.   Especially, as you say, if the RIR allocation
is something larger than /24

And I have a feeling acceptance /24 route announcements of anything
other than legacy classful space, infrastructure space like the root
servers is going to be patchy at best.

2008/12/19 Darryl Dunkin <ddunkin at netos.net>:
>
> If you are allocated a /22, announce the /22. Do not announce  
> anything longer unless you have a requirement to (such as a  
> different origin AS). If you are further allocating a subset of that  
> to a downstream, then a /24 out of that is acceptable as the origin  
> will be different.
>