Stephane, can you update the tooltip on subgraph to indicate it will
lead to more crossed lines on larger graphs because it tries to keep
children order?

Note the tooltip currently has the following:

"Subgraphs can help GraphViz position spouses together, but with non-trivial graphs will result in longer lines and larger graphs."

From that tooltip, looks like my previous e-mail was wrong -- subgraphs aren't used to keep children together, but spouses together.

What text do people want in the tooltip instead?