In this post,I will give a list of all undocumented parameters in Oracle 11g. Here is a query to see all the parameters (documented and undocumented) which contain the string you enter when prompted:

– Enter name of the parameter when prompted

SET linesize 235
col Parameter FOR a50
col SESSION FOR a28
col Instance FOR a55
col S FOR a1
col I FOR a1
col D FOR a1
col Description FOR a90

SELECT
 a.ksppinm "Parameter",
 decode(p.isses_modifiable,'FALSE',NULL,b.ksppstvl) "Session",
 c.ksppstvl "Instance",'F','TRUE','T') "S",
 decode(p.issys_modifiable,'T','IMMEDIATE','I','DEFERRED','D') "I",
 decode(p.isdefault,'T') "D",
 a.ksppdesc "Description"
FROM x$ksppi a,x$ksppcv b,x$ksppsv c,v$parameter p
WHERE a.indx = b.indx AND a.indx = c.indx
 AND p.name(+) = a.ksppinm
 AND UPPER(a.ksppinm) LIKE UPPER('%&1%')
ORDER BY a.ksppinm;

Enter value for 1: