Hello,
As far as I know Oracle has never published any article on coding standards. I've seen many people using capitals and few use small case letters while developing the code.
today when I'm going through few built in packages like dbms_output, dbms_utility, utl_file etc. I was surprised by seeing different coding standards followed for each package.
copied below piece of code from dbms_utility package specification.
type maxname_array IS table of VARCHAR2(32767) index by BINARY_INTEGER;
-- Lists of large VARCHAR2s should be stored here
type dblink_array IS table of VARCHAR2(128) index by BINARY_INTEGER;
-- Lists of database links should be stored here
TYPE index_table_type IS TABLE OF BINARY_INTEGER INDEX BY BINARY_INTEGER;
-- order in which objects should be generated is returned here
TYPE number_array IS TABLE OF NUMBER INDEX BY BINARY_INTEGER;
-- order in which objects should be generated is returned here for users.
TYPE instance_record IS RECORD (NUMBER,VARCHAR2(60));
-- Suri