No description of ATTR_DEFAULT_IDENTIFIER_OPTIONS now in "Chapter 4 Configuration"

In the previous (1.1) documentation version there were small but useful description about how to set up primary key (http://www.doctrine-project.org/documentation/manual/1_1/en/configuration#defaults-attributes:default-added-auto-id)
Now there is nothing about ATTR_DEFAULT_IDENTIFIER_OPTIONS and it takes about 20 minutes to debug and find out where did "id" field added

ps: message "If you find a problem with the documentation or have a suggestion, please register and open a ticket. " in the bottom of the docs pages is ambiguous due to it points to trac :-$