Protools playback and record shortcut keys

space: play / stop
shift+space: playback at half speed
F12: record enable

with record enabled:
space: begin recording / stop recording
shift+space: begin recording at half speed

Sources for protools playback and record shortcut keys

Source: Protools Shortcut keys PDF
Source: Protools MAC Shortcut keys PDF
Source: Protools WINDOWS Shortcut keys PDF