Corporate sustainability reports often deal with environmental issues, less so matters of workplace diversity. That may start to change if more companies follow Apple's lead.

Amid the backdrop of shareholders and activists pressuring tech companies to foster a more diverse workforce, Apple CEO Tim Cook has announce that, in the near future, it will release a diversity breakdown of its more than 80,000 employees. Cook revealed those plans in a recent interview with Bloomberg News. The release of that data ties to Apple's ongoing pledge to foster a more diverse workforce.

Apple is not alone among the tech giants disclosing workforce data. Google recently offered a similar breakdown. Its workforce is 70 percent male and 30 percent female; the ethnic breakdown is 61 percent white, 2 percent black, 30 percent Asian, and 3 percent Hispanic. Business social networking site LinkedIn has also disclosed an employee review: 61 percent male, 39 percent female, 53 percent white, 38 percent Asian, 4 percent Hispanic, and 2 percent black. Facebook dedicates a page to updating its diversity initiatives and eBay says it also plans to do so.

Calvert Investments, an activist fund, rated the diversity policies of S&P 100 companies last year. Silicon Valley tech companies rated poorly in that assessment, in particular for the lack of women and minorities being represented on boards and in executive positions. Topping the list with favorable diversity practices were Citigroup, Coca-Cola, and JPMorgan Chase; languishing near the bottom were eBay, Berkshire Hathaway, and Simon Property Group.

While the current batch of company disclosures were made voluntarily, regulatory requirements are on the horizon. Currently in the proposed rule stage, six federal regulators that oversee financial institutions are preparing requirements that companies reveal more about the composition of their workforce, including information on gender, race, and whether workers are veterans or disabled. New York state officials are also demanding that large several companies—among them Apple, Pfizer, and Qualcomm— shed more light on diversity issues throughout their supply chains. While the Securities and Exchange Commission already requires public companies to report on board diversity, California is the first state to enact quotas for it.