No, overseeding is something different. The best practice for planting perennial clover is to mix the clover with a cereal grain. For most folks, the best one to use is Winter Rye (WR). The winter rye acts as a nurse crop. Some folks use the term cover crop, but this term has several meanings depending on context, and nurse crop has only one. It is a companion plant intended to "nurse" the clover crop until it is well established. Winter rye is an annual that germinates quickly. Deer love it when it is young and tender. You are best to plant right before a good rain in the fall. A nominal rate is 100 lbs/ac of Winter Rye and 10 lbs/ac of perennial clover. Those rates can vary quite a bit based on conditions and the type of clover chosen, but it is a good starting place. Generally, fall weeds are not an issue. Conditions favor crops like WR and Clover at this time of year. The clover will typically germinate but you won't get much growth. The WR is the attractant that first fall when planted.
By spring, the winter rye will really take off smothering the field. This keeps weed seeds from germinating and growing simply by depriving them of light and resources but also by a chemical effect WR specifically has on many weed seeds. The clover, which has already germinated and gone dormant over the winter will spend the spring using most of its energy to put down a good root system. This is when mowing is critical. You want the nurse crop of winter rye to continue to live and keep weeds at bay, but you don't want it to shade out your clover slowing its development. So, each time the WR hits a foot or so tall, it is time to mow. You want to mow it back to 6" - 8" depending on conditions. The lighter you seeding rate of WR, the less critical mowing is but the more opportunity you have for weed establishment. Taller growing clover varieties that are less drought tolerant or no rain the forecast call for mowing higher. If you use a drought tolerant lower growing clover like Durana, you can usually mow lower, but if conditions are dry enough you still might want to shoot for 8" rather than 6".
This mowing the first spring creates a balance. The winter rye nurse crop continues to fight weeds until it naturally dies in the summer. The clover is released and fills in as the WR naturally dies. Mowing generally does not impact grass type weeds, but it does control most broadleaf weeds. With this approach you start off with a field that is very clean for a low cost with no herbicides. After the clover is well established (by that second fall) it will be a clean clover field and the clover will be the attractant. Generally, at this point overseeding is a waste of time because the clover is so thick and there is really no need.
Each year, as individual clover plants die and are replaced, more N is released into the soil. Grasses love N, so over time the field will become more and more weedy. I don't mind this at all. I don't use herbicides each year on clover and I let the weeds grow during the spring and summer. They actually shade the clover and many broadleaf weeds are good deer food. Each fall, as the nights get cooler and fall rains come our way, I will mow the field back to 6" to 8". Removing the overstory of weeds and the changing weather conditions favor the clover. I typically have a high percentage of clover in the fall even in fields that looked like they just had weeds in the summer. However, eventually the weeds will take over. Depending on the clover type and your conditions, this can be from 5 to 7 years after planting.
At this point, I generally spray the field with 1 quart/ac of glyphosate. Clover is naturally resistant to glyphosate. 1 qt/ac will top kill the clover but leave the root system intact. It will kill most grasses and many broadleaf weeds. This is where overseeding comes in. I have a seed drill. I like to drill groundhog radish into the clover when it has been suppressed by gly. I know others have had success simply surface broadcasting at this point. The key to this technique is timing. The gly will stress the clover so you don't want to do it at a time when the clover will be undergoing other stresses. That could kill it. Instead, you want to do this at a time of year when you expect to have a good rain in a few days.
Well, that is how a nurse crop works and more.
Best of luck,
Jack