parameter.issys_modifiable for some hidden parameters

Hello!

Can You please kindly explain,

how to determine the possibility of dynamic updates of some hidden parameters ?

why the view v$parameter.issys_modifiable don't reflect this information?

 select

 a.ksppinm "Parameter",

 decode(p.isses_modifiable,'FALSE',NULL,NULL,NULL,b.ksppstvl) "Session",

 c.ksppstvl "Instance",

 decode(p.isses_modifiable,'FALSE','F','TRUE','T') "S",

 p.issys_modifiable,

 decode(p.isdefault,'FALSE','F','TRUE','T') "D",

 a.ksppdesc "Description"

from x$ksppi a, x$ksppcv b, x$ksppsv c, v$parameter p

where a.indx = b.indx and a.indx = c.indx

 and p.name(+) = a.ksppinm

 and a.ksppinm in (