On January 27, 2012, we reported that Heidi Klum and Seal had decided to end their marriage with Heidi filing documents with the Los Angeles Superior Court. In those documents, Heidi requested joint legal custody of the couple's four children (three with Seal and one from Heidi's previous relationship) with visitation rights for Seal.

However, on April 10, 2012, Seal filed court documents asking for joint physical custody of the children.

While it may seem, at first glance, that Seal is asking for the same rights to the children as Heidi is, the reality is that this is a case of poor wording selection and confusing legalese.

In plain English, what Heidi was asking for was the ability to make all major decisions relating to the children's well-being, education, health and religion jointly with Seal. In addition, she wanted Seal to visit with the children, according to an agreed-upon schedule. However, the children would primarily reside with Heidi.

Now, with his filing, Seal has in a way contested that. He has now asked for joint physical custody of the children. Therefore, he does not want to simply visit with the children according to a defined schedule. Rather, he wants the children to reside with him basically as much as they reside with Heidi.

In Ontario, this is referred to as shared custody. Shared custody refers to arrangements where a parent has physical custody of a child for not less than 40 percent of the time over the course of a year.

What implications could a shared custody arrangement have on separated parents?

In Ontario, one of the implications in implementing a shared custody arrangement is child support. Because the children are now residing with both parents, almost equally, each parent becomes sort of eligible for child support on behalf of the children.

To address this, the Child Support Guidelines created a "set-off" approach. Essentially, once the parent has met the 40 percent threshold, then the applicable federally prescribed Table amounts for each parent are determined and then subtracted one from the other. The amount remaining represents the child support that becomes payable to the parent with the lower income.

However, this is just the first step in determining a child support award in shared custody arrangements. Because, once set-off has been determined, other factors such as the increased costs associated with shared custody and the conditions, means, needs and other circumstances of each parent and child are considered until eventually an appropriate amount is selected. Therefore, the final amount awarded following this analysis can either be higher or lower than that reached with the set-off approach.

If this matter were being heard in Ontario, it could be argued that the child support implications in a shared custody arrangement are a fuelling factor as to why Seal is now seeking joint physical custody of the children. In short, Seal could be angling for child support from Heidi, who has a much higher net worth.

It is definitely no secret that Heidi Klum is an incredibly lucrative brand: she has an approximate annual income of $20 million dollars and a net worth of about $70 million. Seal, on the other hand, has been less than active in the music industry lately and has an estimated net worth of $15 million.