what are all possible filters to add to a server-side trace? On this question you can see how to set up a filter on your trace.

this code below filters a trace file to capture only events that happen on database 'AdventureWorks'

-- Set the Filters
declare @intfilter int
declare @bigintfilter bigint

set @bigintfilter = 1000000
exec sp_trace_setfilter @TraceID, 13, 0, 4, @bigintfilter

exec sp_trace_setfilter @TraceID, 35, 0, 6, N'AdventureWorks'

-- Set the trace status to start
exec sp_trace_setstatus @TraceID, 1


from the example above:

1) what is 13?

2) I know that 35 must be database Name. 

How can I find what could be the other options (hostname, program, ObjectName, etc?) where are them stored? which system table or view?

Here you can see what filters you have on your trace.

I found this link helpful:
Need sp_trace_setfilter xref list of @columnid parameters
from this question: Find out what columns are in a trace file

there is this script

--  Gets all Events for a given trace id
SELECT a.[EventID], b.[name] AS [Even Name], a.[ColumnID], c.[name] AS [Column Name], d.[name] AS [Category]
FROM fn_trace_geteventinfo(&lt;trace ID&gt;) AS a --&lt;&lt;Put the trace ID you are interested in
    INNER JOIN sys.trace_events AS b ON a.EventID = b.Trace_Event_ID
    INNER JOIN sys.trace_columns AS c ON a.ColumnID = c.Trace_Column_ID
    INNER JOIN sys.trace_categories AS d ON b.Category_ID = d.Category_ID
ORDER BY a.[EventID], a.[ColumnID]


that shows all the columns of a trace, due to the DMV sys.trace_columns



I have put in place a server side trace with the following filters:
(this is part of the script)

-- Set the Filters
declare @intfilter int
declare @bigintfilter bigint

exec sp_trace_setfilter @TraceID, 10, 0, 7, N'SQL Server Profiler - 53e0541a-7b74-4fce-bcac-9255e79a6372'
exec sp_trace_setfilter @TraceID, 34, 1, 6, N'udpProductTaxRateGet'
exec sp_trace_setfilter @TraceID, 34, 1, 6, N'udpProductBulletPointSelectByTier1NoteTypeCode'
exec sp_trace_setfilter @TraceID, 35, 1, 6, N'US16AUTPProduct'
-- Set the trace status to start
exec sp_trace_setstatus @TraceID, 1

-- display trace id for future references
select TraceID=@TraceID


When I run this query now, I can see what columns are there, and exactly how the filters would work.

------------------------------------------------------------
-- what filters are set on @traceid
-- and how they are working
-- marcelo miorelli sql server 2005 - 8-8-2016
------------------------------------------------------------
declare @traceid int
select @traceid = 2
select a.[columnid]

     ,c.[type_name]
     ,c.[name] as [Column Name]

     ,[ @comparison_operator ] = CASE A.comparison_operator 
                                     WHEN 0 THEN '= (Equal)'
                                     WHEN 1 THEN '&lt;&gt; (Not Equal)'
                                     WHEN 2 THEN '&gt; (Greater Than)'
                                     WHEN 3 THEN '&lt; (Less Than)'
                                     WHEN 4 THEN '&gt;= (Greater Than Or Equal)'
                                     WHEN 5 THEN '&lt;= (Less Than Or Equal)'
                                     WHEN 6 THEN 'LIKE'
                                     WHEN 7 THEN 'NOT LIKE'
                                     ELSE 'NOT SURE'
                               END
     ,a.value
     ,[ @logical_operator ]    = CASE A.LOGICAL_OPERATOR 
                                     WHEN  1 THEN 'OR'  
                                     ELSE         'AND' 
                                 END
 from fn_trace_getfilterinfo( @traceid ) a
    INNER JOIN sys.trace_columns AS c ON a.ColumnID = c.Trace_Column_ID





  --[ @logical_operator = ] logical_operator
  
  --Specifies whether the AND (0) or OR (1) operator is applied.
  
  --logical_operator is int, with no default.