These posting types are used for calculated tax codes (reverse charge type tax codes either for EU reverse charge or domestic reverse charge) where IFS calculates the debit and credit posting (IP9 and IP10 respectively) but the total VAT is zero. 

We typically suggest to post these to a different accounts to make analysis and recs of the standard VAT codes easier and separated out. If both domestic and EU reverse charge applies, you could even create separate accounts for each type of tax, depending on how many transactions go through these accounts. 

Hi,

usually the posting type: IP9 Tax Received, Calculated is set in the same account as account in the posting type: IP3 Tax Receive, Invoice. The posting type: IP10 Tax Disbursed, Calculated is set in the same account as account in the posting type: IP4 Tax Disbursed, Invoice.

Best regards,

Małgorzata