nginx undocumented directives

[Gena Makhomed]

Hello, All!

Scanning nginx sources and nginx documentation
I found some directives, which present in nginx sources
but absent in nginx documentation:

acceptex_read
degradation
degrade
devpoll_changes
devpoll_events
epoll_events
eventport_events
gzip_hash
gzip_no_buffer
gzip_window
http2_pool_size
http2_streams_index_size
iocp_threads
kqueue_changes
kqueue_events
post_acceptex
post_action
postpone_gzipping
smtp_client_buffer
smtp_greeting_delay
ssi_ignore_recycled_buffers
uwsgi_string

post_action is known dangerous directive, it undocumented
by purpose and in vim syntax file it marked accordingly:

syn keyword ngxDirectiveError contained post_action

But what about all rest undocumented directives, they are undocumented
by purpose or through inadvertence, and may be in the near future
all it (except post_action directive) will be documented?

And second question: how they are should be marked in nginx syntax file,
as normal nginx directives, or color mark it as undocumented directives?

For example:

syn keyword ngxDirectiveUndocumented contained acceptex_read
syn keyword ngxDirectiveUndocumented contained degradation
...
syn keyword ngxDirectiveUndocumented contained uwsgi_string

hi link ngxDirectiveUndocumented Constant

-- 
Best regards,
  Gena