Hi, I received Form 3531 (Request for Signature or Missing Information to Complete Return). Would should I fill in?

[libragopi]

Form 3531 had these items checked. 
- Complete Schedule 1 to support your entry on line 8 of Form 1040. 
- Complete Schedule 2 to support your entry on line 23 of Form 1040. 
- Complete Schedule 3 to support your entry on line 20 of Form 1040. 
- Complete Schedule 4 to support your entry on line 12 of Form 1040. 

[Critter-3]

I bet you mailed in the return but failed to include all the pages required since the IRS is asking for this information now ... please provide them with the info they want asap as your return will remain in processing limbo until you do.  They are asking for Schedules 1 - 4 ... print them off and send them.