Months after the Internal Revenue Service acknowledged that it had singled out for extra scrutiny conservative and Tea Party groups seeking tax exempt status, the agency Tuesday proposed regulations that would clarify some of the rules for those tax-exempt groups.

The situation for tax-exempt social welfare organizations, or 501(c)4s, is pretty complicated, but the new proposals are one attempt to iron out one of the murkier questions: What exactly constitutes "candidate-related political activities?"

None of this is final yet, because the IRS is seeking public comment. And the person President Obama put in charge to oversee the agency's recovery from the scandal, IRS Acting Commissioner Danny Werfel, is still on the job. But here are a few things to know:

What does this have to do with the Tea Party?

Earlier this year, the IRS admitted that it had inappropriately scrutinized the Tea Party and other conservative groups that were applying for tax-exempt status, sometimes delaying their applications for many months.

Though Republicans have suggested that there were political motivations for this, the IRS has insisted that its employees had set aside the applications to figure out whether these groups were engaged in so much political activity they couldn't possibly qualify for tax-exempt status.

In some cases, the IRS actually asked for an inordinate amount of documentation, or probed the groups for information (such as what books were on their reading lists).

What are the rules now?

These groups are governed by a fairly vague standard: They can't be "primarily engaged in express political advocacy but have to be focused mostly on "social welfare" activities.

What does that mean, exactly? Well that's what the IRS wants to know.

The IRS has proposed a definition of "political activities" (we'll get to that later), but it is soliciting comment from the public about what exactly "primarily" means.

Many campaign finance lawyers interpret that to mean that more than 50 percent of their activities have to be nonpolitical. Others interpret that to mean 60 percent, or 80 percent, so on and so forth.

The IRS will eventually decide whether that word "primarily" needs to be clarified, and if so, what it should actually mean.

What does the IRS want to consider a "political activity"?

That's easy. In its proposal, the IRS laid out several things that would be considered "political activities." Its recommendations are subject to input from the public. But presumably, they are intended to reduce the amount of onerous inquiries IRS agents have to make in order to figure out what groups are actually doing with their time and money.

Among the activities that are considered "political" are "get out the vote drives," materials that advocate for a specific candidate, hosting a candidate for an event within 60 days of a general election or 30 days of a primary and making financial grants to other groups (527 political organizations or other tax-exempt groups) that do explicitly advocate for a candidate, unless they state that the money won't be used for those activities.

Why does this even matter?

The uncertainty about what 501(c)4 groups can and can't do has been a pretty big political issue since the 2010 elections.

That's when nonprofit groups like Crossroads GPS, which is backed by conservative strategist Karl Rove, jumped into the political arena. And it was later followed by Priorities USA, founded by former Obama administration officials and Organizing for Action, a group founded from the remnants of Obama's 2012 campaign.

Since these groups aren't obligated to disclose their donors, some believe there should be tighter rules governing their activities.

To be sure, most of the big groups hire lawyers to make sure they stay within the letter (and perhaps the spirit) of the law. But the law is actually pretty vague. And many Democrats believe it should be significantly tightened.

Republicans, like House Oversight Committee Chairman Darrell Issa, R-Calif., reacted to the announcement today by denouncing the administration's attempts at "stifling constitutional free speech."