LinkedIn Recruiter has added a few new field definitions -- I recently asked LinkedIn Customer Service to define the source of the data. Here's the response --
1. Company type- This matches to the current company only on a person's profile. The type is derived from a proprietary algorithm created by the search team and is not user inputted.
2. Fortune- This is also driven by current company only, deducted from their profile.
3. Years of Experience: This is determined by the total number of years all the positions on their profile add up to.
4. Years at Current Company: This is "smart" enough to recognize past and current positions at the same company, and does take those into account in bucketing profiles correctly.
5. Function: This is not inputted by the user, but is determined by the algorithm, which takes a current job title into account when determining which function to list someone as.
6. Seniority: This is not user-inputted. The algorithm matches current job titles into Seniority categories.
7. Industry: This is based off the industry the user inputs on their profile and is not related to company profile information.