pgrestore, notice, will create implicit.

Hello,

I am trying to restore a database with pg_restore,
(psql 7.4.6 on Linux 2.6.9-5.ELsmp (RedHat 4))
but I do not understand what the specific -notice- messages mean
that the pg_restore produces:

pg_restore -O -Fc -d DataBaseOmr -v </var/tmp/DataBaseOmr.cdump

pg_restore: connecting to database for restore
pg_restore: creating FUNC PROCEDURAL LANGUAGE plpgsql_call_handler()
pg_restore: creating PROCEDURAL LANGUAGE plpgsql
pg_restore: creating ACL public
pg_restore: creating TABLE omroepevent
pg_restore: creating ACL omroepevent
pg_restore: creating FUNCTION funcomroepevent0()
pg_restore: creating TABLE omroepbericht
pg_restore: NOTICE: CREATE TABLE will create implicit sequence
"omroepbericht_omroepberichtid_seq" for "serial" column
"omroepbericht.omroepberichtid"
pg_restore: creating ACL omroepbericht
pg_restore: creating ACL omroepbericht_omroepberichtid_seq
pg_restore: restoring data for table "omroepevent"
pg_restore: restoring data for table "omroepbericht"
pg_restore: restoring data for table "BLOBS"
pg_restore: restored 0 large objects
pg_restore: creating INDEX omroepbericht_receivedlocal_idx
pg_restore: creating CONSTRAINT omroepbericht_pkey
pg_restore: NOTICE: ALTER TABLE / ADD PRIMARY KEY will create implicit
index "omroepbericht_pkey" for table "omroepbericht"
pg_restore: creating TRIGGER triggeromroepevent0
pg_restore: executing SEQUENCE SET omroepbericht_omroepberichtid_seq
pg_restore: creating COMMENT SCHEMA public

Can someone please tell me what
"will create implicit sequence"
and
"will create implicit index"
means ?

Thanks,
Marcel.