When you receive or have a call on your yealink phone and want to put them on hold to ask someone else in your office a question, the phone transfers instead of holding.
When you put someone on hold either by the display soft key or the hold button on the phone, in order to call someone else in your office you need to create a new call or use a second line. In some cases you will only have one line appearance, so your only choice is to push the "NewCall" soft key in the phone display. Then you can either enter the extension you want to call or push a speed dial/BLF key for that extension. Complete/End your call with them and then you can go back and push the "Resume" soft key in the display.