Such comments can be stored with the comment SQL verb.
select
column_name,
comments
from
dba_comments
where
owner = 'RENE' and
table_name = 'TAB_XYZ'
;
Find columns with a given name and show the table and column comments:
select
col.table_name,
col.column_name,
col.owner,
col.data_type,
tcm.comments comment_tab,
ccm.comments comment_col,
obj.object_type,
obj.subobject_name
from
dba_tab_cols col left join
dba_objects obj on col.owner = obj.owner and
col.table_name = obj.object_name left join
dba_col_comments ccm on col.owner = ccm.owner and
col.table_name = ccm.table_name and
col.column_name = ccm.column_name left join
dba_tab_comments tcm on col.owner = tcm.owner and
col.table_name = tcm.table_name
where
col.column_name like '%PK_ID%' and -- <== Enter search pattern here.
obj.oracle_maintained = 'N'
order by
case
when obj.object_type not in ('VIEW', 'TABLE') then 99
when col.table_name like 'BIN$%' then 999
when obj.subobject_name is not null then 9999
else 0
end,
col.table_name;