what is in ../data/base ??

Hello,

I am currently using 7.1.3 on an HPUX-11.00
When I do a ls -al to look at the ../data/base directory here is what i see:

postgres>ls -al
total 52
drwx------ 7 postgres users 1024 Jan 1 18:05 .
drwx------ 5 postgres sys 1024 Jan 1 17:46 ..
drwx------ 2 postgres users 2048 Dec 17 21:40 1
drwx------ 2 postgres users 3072 Dec 31 14:56 184847
drwx------ 2 postgres users 2048 Dec 17 21:34 18719
drwx------ 2 postgres users 7168 Dec 17 22:51 58443
drwx------ 2 postgres users 10240 Jan 1 17:57 5886825
postgres>pwd
/db1240/data/base
postgres>

I don't see the name of the databases I have created !!
Idem inside a database directory. I don't see the name of the tables & index !
Only numbers !

Is it so since 7.1.3 ? It was not the case with 7.0.2 !
Any light on this ?? Have I done something wrong when installing 7.1.3 ?

Thanks.
Pierre.