Some questionable campaign contributions are listed on the Cambridge Civic Journal Web site.

With city councillor Marjorie Decker’s formal declaration to run for Anthony Galluccio’s state Senate seat Tuesday, it seems time to clear up some old business:

In early January a question was raised whether contributions to Decker’s write-in re-election campaign for the council were over the legal individual limit of $500. There were seven contributions to Decker’s campaign that looked higher than allowed, five from unions. The image with this post show some information Robert Winters pulled together for his Cambridge Civic Journal site.

The state Office of Campaign & Political Finance confirms the unions contributing to Decker from $750 to $2,750 were allowed to dispense that much money to a candidate. They are not subject to the same $500 limit as individuals.

The rule is elusive; the office’s chart of limits doesn’t include unions. But general counsel Greg Birne points visitors to Interpretative Bulletin 88-01, which makes it clear unions — as “organizations that do not solicit or receive funds for any political purpose (i.e. to support or oppose candidates …), and whose treasuries do not contain funds derived from business or professional corporations” — can make political expenditures without limit or question until they become “more than incidental.”

Expenditures are “more than incidental” if they exceed, in the aggregate, in a calendar year, either $15,000 or 10 percent of such organization’s gross revenues for the previous calendar year, whichever is less.

A union exceeding the limits would be treated as a political action committee and limited to $500 per candidate per year, and unions must report political expenditures to the office. “Everybody gets an audit of some kind [but] if we get a complaint, we might look at it more quickly,” Birne said.

Union reports are filed rarely, he said. The records are not kept online by OCPF.