TM 1-1510-218-10   3C-55 1.  Line Select Keys 2.  Function Keys 3.  Function Keys 4.  Clear Key 5.  Scroll Keys Figure 3C-23.  Control Display Unit Front Panel Table 3C-13.  FMS-800 CDU Function and Application Keys  (Continued) FUNCTION KEYS KEY DESCRIPTION KEY DESCRIPTION COM Accesses    control    pages    for    UHF/VHF radio. M3 Function not used. DATA Enables display of expanded data for any selected waypoint. MARK Marks and stores present position plus any active  cursor  position  transmitted  from  the Flight Display System (FDS). DIR Enables  immediate  selection  of  Direct-To waypoint. MSN Accesses   a   menu   of   additional   mission functions. EDIT Accesses Flight Plan pages. NAV Accesses the Navigation information page. FPLN Accesses Flight Plan pages. PSN Accesses  Pilot  Position  (present  position and track) pages. IDX Accesses index of additional functions not available on top-level keys. STAT Accesses avionics LRU status pages. IFF Function not used. STR Accesses Pilot Steering pages. INAV Accesses  comprehensive  data  pages  for GPS navigation solutions. APPLICATION KEYS – Deletes  data  from  entry  fields  or  causes data to revert to a default value. ¯ Scrolls vertically to related pages of data or scrolls   down   through   lists   of   data   on   a page. CLR Clears  the  scratchpad  of  incorrect  entries or annunciations. ® Horizontally scrolls right to access additional pages of information. / Separates the waypoint identifier, bearing, and distance components. ¬ Horizontally scrolls left to access additional pages of information. - Scrolls  vertically  to  related  pages  of  data or  scrolls  up  through  lists  of  data  on  a page.