I recently got that question, and in particular, they asked why they sometimes see a Fill Light or Recovery slider (see below left highlighted in red —  the normal Basic panel is shown below right). What’s happened is they’ve opened a photo they edited years ago in Lightroom — before the enhancements that were added to Lightroom editing mathematics a number of versions ago. Back in ‘the old days” the Highlights slider was named the ‘Recovery’ slider (it recovered clipping highlights) but it could only pull back (decrease) the highlights, not like the Highlights...