Hello  
This is probably not related to TDE, but Linux in general (Debian 8?).
I have a multimedia PS/2 keyboard "BTC 9001" (evtest reports it as
"AT Translated Set 2 keyboard") and I try to use all its keys. Some are
typical multimedia keys, while I program some other to launch
applications in my TDE using "Keyboard actions" panel. Unfortunately
not all keys are detected in OS by scancodes. Two keys generate only a
EV_MSC event, while not giving scancode. 
Is it possible, by e.g. udev hwdb rule, to assign scancodes to these
events?  
Here are results of evtest events test:

Testing ... (interrupt to exit) 
Event: time 1470587826.798369, type 4 (EV_MSC), code 4 (MSC_SCAN),
value 1c  
Event: time 1470587826.798369, type 1 (EV_KEY), code 28 (KEY_ENTER),
value 0 
Event: time 1470587826.798369, -------------- EV_SYN ------------
Event: time 1470587829.689519, type 4 (EV_MSC), code 4 (MSC_SCAN),
value 1e 
Event: time 1470587829.689519, type 1 (EV_KEY), code 30 (KEY_A), value
1 
Event: time 1470587829.689519, -------------- EV_SYN ------------
Event: time 1470587829.753248, type 4 (EV_MSC), code 4 (MSC_SCAN),
value 1e  
Event: time 1470587829.753248, type 1 (EV_KEY), code 30 (KEY_A), value
0  
Event: time 1470587829.753248, -------------- EV_SYN ------------
Event: time 1470587836.420023, type 4 (EV_MSC), code 4 (MSC_SCAN),
value e5  
Event: time 1470587836.420023, type 1 (EV_KEY), code 217 (KEY_SEARCH),
value 1  
Event: time 1470587836.420023, -------------- EV_SYN ------------
Event: time 1470587836.504746, type 4 (EV_MSC), code 4 (MSC_SCAN),
value e5  
Event: time 1470587836.504746, type 1 (EV_KEY), code 217 (KEY_SEARCH),
value 0  
Event: time 1470587836.504746, -------------- EV_SYN ------------
Event: time 1470587839.705553, type 4 (EV_MSC), code 4 (MSC_SCAN),
value a6  
Event: time 1470587839.705553, -------------- EV_SYN ------------
Event: time 1470587839.782562, type 4 (EV_MSC), code 4 (MSC_SCAN),
value a6  
Event: time 1470587839.782562, -------------- EV_SYN
------------  
Event: time 1470587840.546297, type 4 (EV_MSC), code 4 (MSC_SCAN),
value a5  
Event: time 1470587840.546297, -------------- EV_SYN ------------
Event: time 1470587840.648616, type 4 (EV_MSC), code 4 (MSC_SCAN),
value a5  
Event: time 1470587840.648616, -------------- EV_SYN ------------
Event: time 1470587842.578400, type 4 (EV_MSC), code 4 (MSC_SCAN),
value 1d  
Event: time 1470587842.578400, type 1 (EV_KEY), code 29 (KEY_LEFTCTRL),
value 1  
Event: time 1470587842.578400, -------------- EV_SYN ------------
Event: time 1470587842.761042, type 4 (EV_MSC), code 4 (MSC_SCAN),
value 2e  
Event: time 1470587842.761042, type 1 (EV_KEY), code 46 (KEY_C), value
1 
Event: time 1470587842.761042, -------------- EV_SYN ------------ 

The keys pressed are: Return key released, A, then "Search"
custom key which works, then "Manual" and "Panel" keys (these two
don't work - no scancode), then ctrl-C to stop evtest.  
MCbx

P.S. And again my webmail removed newlines in my previous post... sorry
for inconvenience, ignore the previous one.