Oregon voters approved the use of medical marijuana in a 1998 ballot measure. Since then, more than 1 percent of the state's population - it works out to nearly 40,000 Oregonians - have received medical marijuana cards.

More than a decade later, we're still working out the myriad of issues - anticipated and not - that have come in the wake of that ballot measure.

In this November's election, Oregon voters get a chance to weigh in on one more of those issues: Ballot Measure 74 would authorize the creation of a statewide dispensary system for medical marijuana.

The measure itself spells out only a few of the details of how that system would work. Proponents of the measure say that task is better suited for state regulators, and so it directs state health agencies to create the rules that would govern the system.

But you know what they say about the devil and details. We worry that Measure 74 is simply too vague and that there's likely to be serious mischief if the measure passes. We recommend a "no" vote.

Under current law, medical marijuana users can grow their own marijuana or designate someone to do that for them. Measure 74 would authorize the creation of dispensaries to sell marijuana to people with medical marijuana cards. Proponents say the measure would provide a safer, more reliable and regulated way to get marijuana without growing it themselves.

But there are catches, and here's a big one: Under the measure, employees of the dispensaries would be immune from criminal prosecution for marijuana-related crimes if they are in "substantial compliance" with the measure.

The measure doesn't define "substantial compliance." Law enforcement officials worry that the measure, as written, would make many drug laws unenforceable.

In addition, the measure sets no limits for the number of dispensaries that could be established statewide. States such as California (a medical marijuana leader) found that they were overrun with dispensaries and had to take steps to cut back.

These are not small details. These are issues that could have been addressed in the text of the measure.

Too often, Oregon ballot measures wind up turning into poster children for the law of unintended consequences. We fear Measure 74 has the potential to join that group.