TM 1-1510-218-10 3B-49 the data base. APT‡4000 FT* ^– Airports having a hard surface runway  at  least  4000  feet  in length.      The   *   denotes   that these   airports   are   presently loaded in the data base. APT‡3000 FT* ^– Airports having a hard surface runway  at  least  3000  feet  in length.    Only  one  of  the  two airport elements may be selected.    No  *  denotes  the element is not presently contained in the data base. RW THRESHOLD * ^– Runway  thresholds  for  which there   exists   verified   latitude and longitude coordinates.   No  *  denotes  the  element  is not presently contained in the data base. OUTER MKR ^– Outer markers. HI ALT WPT ^– High    altitude    waypoints    are named intersections that appear    on    high    altitude    en route charts. LO ALT WPT ^– Low    altitude    waypoints    are named intersections that appear    on    low    altitude    en route charts. DP’s/STAR ^– Departure    Procedures    (DP) and Standard Terminal Arrival Route  (STAR)  waypoints  and intersections. APR INTRSC ^– Approach intersections are named intersections that appear on instrument approach charts.  They do not include   outer   markers   since outer  markers  are  a  separate category. MULT WPT ^– Waypoints  that  are  used  for multiple functions. For example,  if  a  waypoint  serves as both a low altitude waypoint and as an approach intersection, it is considered a multiple waypoint. Also, multiple waypoints include on- airway  NDB's.    If  any  type  of waypoint   (HI   ALT,   LO   ALT, DP/STAR,  or  APR  INTRSC) is loaded in the data base the multiple waypoints are automatically included. (7)   Modify   Data   Base   Page.      This  page  is used to select regions of the world from which data will be  loaded  in  the  data  base.    It  is  one  of  two  pages used    to    configure    the    data    base    to    the    aircraft's specific requirements prior to using the data loader to actually load the data into the data base. SEL MENU ITEM ^– The   number   associated   with the desired menu item can be entered in this field. The regions of the world are the same as those on the review data base page.  The meaning of the *, however,   is   different.      On   this   page   the   *   denotes those  regions  of  the  world  that  will  be  loaded  by  the data  loader.    The  *  on  the  review  data  base  page denotes  those  regions  of  the  world  that  are  currently loaded in the data base. (8)   Modify   Elements   Page.      This   page   is used to select the navigation elements for a particular region  of  the  world  that  will  be  loaded  into  the  data base with the data loader. BLKS AVAIL ^– The number of blocks of data base  memory  remaining  (for entire     data     base,     not     just region  being  displayed).    The number  decreases  each  time an element below is selected. NAVAID * ^– The data base elements listed are the same ones described on the review elements page.   The number to the right of the element    is    the    number    of blocks   required   to  store  the element     in     the     data     base memory  for  the  region  of  the world displayed.  No numbers appear next to RW THRSHLD or  OUTER  MKR  until  one  of the two APT (airport) elements  has  been  selected.   Whenever   any   or   all   of   the waypoint    elements    (HI    ALT WPT,    LO    ALT    WPT,    DP/ STAR, or APR INTRSEC) are selected,   the   MULT   WPT   is automatically included.  MULT WPT cannot be selected unless at least one of the four waypoint elements is selected.