Brent Ozar First Responder Kit filter About once a week the query 
sp_Blitz @IgnorePrioritiesAbove = 50, @CheckUserDatabaseObjects = 0
 shows "errors" with DB backups that are very old. 

It's correct to show this, but is it possible to filter this error in case of availability group DB's which are on a secondary node and are not backed up (I'm using Ola's scripts to backup the DBs)?
Yes, you can use the @SkipChecks parameters for this. Create a table with columns for:


DatabaseName NVARCHAR(128)
CheckID INT
ServerName NVARCHAR(128)


Then populate it with the list of databases &amp; checks you want skipped. For example, if you want check 52 skipped for all databases, add a row with CheckID 52, and databasename null. If you want check 52 only skipped for the WebSite database, add a row with DatabaseName = WebSite, CheckID = 52.

Then when you run sp_Blitz, populate these parameters:


@SkipChecksDatabase - the database where your SkipChecks table lives, like DBAtools
@SkipChecksSchema - the schema, like dbo
@SkipChecksTable - the name of the SkipChecks table (could be BlitzSkipChecks for example)