It is clearly stated in the rules that Memory Units (MU) only apply to 'installed' programs. By 'installed' I mean installed on the runner's rig.
Then I read the ZU.13 Key Master card:
[...]the memory cost of ZU.13 Key Master is 0, even if it is not installed.
This seems to imply that a program's MUs count even when not installed. As if they would count in your grip. Nothing in the rules supports that.
Can someone explain this card please?