Parenting an Object with "Parent Type: Curve" is weird

Hi everyone,
In the Relations tab in the Object Properties Context there is a way to parent the selected object to another and to choose the type of parenting. All options are clear and well documented but I really can’t figure out what the Curve parent type is used for or how to use it.
Every time I parent a solid or a curve, either open or closed, to a curve, either open/closed Bezier/NURBS, I get nothing. All I see is some really weird stuff when I grab the parented object and move it around. On top of that I didn’t find any info about this parenting type in the manual.
Can anybody tell me if this is my ignorance at work or if I should report this as a bug?

Thank you.

Ver 2.74.5 Linux32