OSHA is on a mission to improve the tracking of workplace injuries and illnesses. Last year it issued a rule that certain employers, including many construction companies, have to electronically file an annual injury and illness log summary — information from Form 300A —  via the Injury Tracking Application (ITA). By publishing these log summaries on its website for all the world to see, OSHA hopes to incentivize employers to reduce their injury rates.

The deadline for filing 2016 data was December 31. But it seems some contractors didn’t get the message or decided to ignore it. OSHA reportedly received thousands fewer reports than it expected. Whether contractors forgot to file, didn’t know they had to or decided it was against their interests, those who needed to file and didn’t are subject to fines.

Here are seven things to know about the electronic submission of injury and illness data from Form 300A.

1. What is Form 300A? Form 300A is a summary of all the deaths and reportable injuries and illnesses that companies are required to record using Form 300. It shows the injury and illness totals for the year in each category.
2. Who has to file electronically? Employers in construction, manufacturing, remediation and other high-risk businesses with at least 20 employees in any one establishment (branch or office) have to file annually, with the exception of companies in State Plan states, most of which have substantially similar requirements. Starting in 2018, companies with 250 or more employees also have file Forms 300 and 301. You must file form 300A even if you have no injuries or illnesses to report.
3. Which injuries and illnesses count? In order for the injury and illness summary (Form 300A) to be accurate, all reportable incidents must be logged on Form 300 throughout the year. Work-related injuries and illnesses that result in death, loss of consciousness, days away from work, restricted work activity, job transfer or medical treatment beyond first aid must be reported. So must any significant work-related injury or illness that is diagnosed by a doctor, any work-related cases of cancer or chronic irreversible disease, a fractured or cracked bone, a punctured eardrum and noise-related hearing loss of a certain degree.
4. When could you be fined for not filing? OSHA has until June 15 to inspect locations for violations of the electronic reporting rule.
5. Is it too late to file 2016 data? Yes, it’s too late. The ITA is no longer accepting 2016 data. But having a paper version of Form 300A for 2016 ready to present upon inspection and filing your 2017 data now could potentially help you avoid a fine.
6. When are submissions of 2017 data due? You can electronically file your 300A data from 2017 any time between now and July 1, 2018. 
7. How do you file? OSHA’s Injury Tracking Application website lets you submit the data three ways: You can manually enter it into a web form, upload a CSV file to process single or multiple establishments at the same time, or transmit data from an automated recordkeeping system via an API (application programming interface) on the website.

Marianne Wait is an editor and writer who creates content for Fortune 500 brands.