Limited information in that link.

Best guesses as to what is happening..

1. Day care providers are writing receipts for each other claiming to have each other's children in their care. So, if a day care is limited to 5 children including her own, they take on 3 day care clients. Another provider in the same situation does the same. Normally, own children don't bring in income and can't be claimed as business expenses. By pretending they have each others they can claim food and other expenses for all.

2. Similar to above but worse, no money exchanges hands and children stay in own homes. Day care provider writes receipt for income of other providers child who she hasn't had, maybe with false SIN or transposed numbers or maybe without a SIN and provider then claims back child care fees they haven't actually paid out from taxes.

3. Maybe they write each other receipts for items advertised on Kijiji allowing day care provider to claim for toys and equipment they don't have/didn't buy.