Some money in politics issues are truly, frustratingly complicated. At other times, what seems complex might actually be a matter of inside baseball, explanations that only beltway insiders know and understand by heart. The rest of us might not be privy to some of the more intricate and complex rules and practices that are employed by special interests in their attempts to influence policy. Here's a handy guide to some of the "tricks of the trade" that you might not be aware of.

At first glance, calculating how much money is spent on lobbying should be straightforward. The Center for Responsive Politics has been providing this information since 1996, and in 2012 the figure reached $3.3 billion. So, what's the concern? In fact, there are good reasons to be skeptical that the number accurately represents the full extent of lobbying activity in the U.S.

Under the radar

For one thing, the totals reported on lobbying disclosure forms include only money paid out by groups that spend at least $12,500 in a quarter on their own lobbying campaigns. Groups that spend $12,499 or less in a quarter need not disclose, and we know little about the ways they are trying to influence public policy. Outside contractors (K Street firms, for instance) hired by organizations to lobby for them have to report lobbying that is billed at more than $3,000 in a quarter. That's substantially lower than the "in-house" threshold of $12,500, but still doesn't show a full and accurate total.

Even groups that do report some lobbying activity are not required to disclose exactly how much they spend. The Lobbying Disclosure Act requires disclosure to the nearest $10,000 in a quarter, so clients will often round their totals up or down. Groups that spend less than $5,000 in a quarter can say they spent nothing. In 2012, more than 1,800 clients reported totals of $0, which could actually represent a total of $9.2 million spent in that calendar year -- but we can't know that for sure.

"Advisors" have the best gigs

A more significant level of undercounting is likely due to a carve-out in the law that allows some highly-paid political operatives to avoid disclosing any of their lobbying activities.

For example, former members of Congress, including both former Senate Minority Leader Tom Daschle (D-S.D.) and former House Speaker Newt Gingrich (R-Ga.), work in "government relations," but have never registered as lobbyists. They and other former lawmakers who work for lobbying firms after they leave the Hill often call themselves "advisors." (See item #6, "Going for a Spin.") By dodging registration requirements, these highly-valued and paid political influencers may be earning large amounts of money to influence policy, but the public can never know.

These weaknesses in reporting regimes show just how slippery the reported dollar amounts can be. The legal definitions of lobbying activity also provide a fair bit of wiggle room. If a lawmaker's office initiates contact with an organization to set up a meeting, for example, that meeting needn't be disclosed and expenditures related to it needn't be included in reported lobbying expenditures.

Similarly, even though some groups do disclose this activity, grassroots lobbying generally doesn't need to be reported. Organizing fly-outs, sending newsletters to an organization's members and similar activities don't count as lobbying under the Lobbying Disclosure Act. The Christian Coalition reported spending millions of dollars on lobbying in the late 1990s, but has reported next to nothing in more recent years because it ceased reporting spending on grassroots activity.

Who's on the receiving end?

Lobbying clients must disclose which federal agencies they lobby, but not the names or titles of the individuals with whom they meet. Even if a client lobbies just one senator, this contact is written on lobbying disclosure forms as "U.S. Senate." Even if the client is granted special access to the president himself, that person or company or other entity would report having met with the "Executive Office of the President."

This level of disclosure adds little to a citizen's understanding of who has access to government. In 2012, nearly every lobbying client reported lobbying the House and Senate, making it impossible to determine who was targeted and whether those officials were in positions to grant favors to campaign donors or allow special access for lobbyists who used to work on the Hill.

The incomplete information leaves many questions that cannot be answered. Citizens might be able to see that the total amount spent on lobbying increased during periods when high-profile legislation was being considered. But did the lobbying client that spent the money oppose the legislation, or support it? Did lobbying clients target one member of Congress who then slipped an amendment into the legislation at the last minute, such as reportedly happened here? Were those clients donors to that lawmaker? Simply knowing that a company lobbied the "U.S. House" reveals little about what the lobbying campaign looked like and how moneyed interests might be playing a role in influencing policy.

Restrictions prohibit certain former government workers from lobbying their former agencies. But since the public is never told who was lobbied, it's impossible for a watchful citizen to determine if someone violates these restrictions. The Center's Revolving Door database documents many cases of former high-profile congressional staffers who now work as lobbyists, but lobbying disclosure forms are silent as to whether they lobbied their former employers.

Lobbying clients don't lobby only for or against new laws. They often also spend substantial amounts of money pressing their arguments at federal agencies. In 2012, more than 1,000 clients lobbied the Department of Health and Human Services, but the public can know very little about which divisions were targeted, how much money was spent, what specific rules and regulations were discussed, and which staff members met with lobbyists. Lobbying clients don't have to, and usually won't, give out that information.