From which (nīti?)śāstra
could come the following śloka about the six 'īti' :

ativṛṣṭir anāvṛṣṭir  mūṣikāḥ śalabhāḥ śukāḥ |
pratyāsannāś ca rājānaḥ  ṣaḍ eta ītayaḥ smṛtāḥ ||   

PW gives a slightly different version with a reference to Parāśara, according to the abdakalpadruma
ativṛṣṭir anāvṛṣṭiḥ śalabhā mūṣikāḥ khagāḥ 
pratyāsannāś ca rājānaḥ ṣaḍ eta ītayaḥ smṛtāḥ ..  Parāśara  im Śkdr. 

–––––––––––––––––––
Christophe Vielle
Louvain-la-Neuve