diff --git a/include/commodity.h b/include/commodity.h
index 41573303..46a038eb 100644
--- a/include/commodity.h
+++ b/include/commodity.h
@@ -43,8 +43,8 @@
 struct comstr {
     /* initial part must match struct empobj */
     short ef_type;
-    natid com_owner;
     short com_uid;
+    natid com_owner;
     /* end of part matching struct empobj */
     i_type com_type;
     int com_amount;
diff --git a/include/empobj.h b/include/empobj.h
index 97dc00e5..8300211f 100644
--- a/include/empobj.h
+++ b/include/empobj.h
@@ -52,8 +52,8 @@
 
 struct empobj {
     short ef_type;	/* is always valid */
-    natid own;		/* is valid if EFF_OWNER   is set in table def. */
     short uid;
+    natid own;		/* is valid if EFF_OWNER   is set in table def. */
     coord x;		/* is valid if EFF_XY      is set in table def. */
     coord y;		/* is valid if EFF_XY      is set in table def. */
     signed char type;	/* is valid for sectors and units */
diff --git a/include/game.h b/include/game.h
index 2e329248..5d0d897b 100644
--- a/include/game.h
+++ b/include/game.h
@@ -39,6 +39,7 @@
 struct gamestr {
     /* initial part must match struct empobj */
     short ef_type;
+    short game_uid;
     /* end of part matching struct empobj */
     char game_upd_disable;	/* updates disabled? */
     /*
diff --git a/include/land.h b/include/land.h
index 339cf410..bd497231 100644
--- a/include/land.h
+++ b/include/land.h
@@ -49,8 +49,8 @@
 struct lndstr {
     /* initial part must match struct empobj */
     short ef_type;
-    natid lnd_own;		/* owner's country num */
     short lnd_uid;		/* unit id (land unit) */
+    natid lnd_own;		/* owner's country num */
     coord lnd_x;		/* x location in abs coords */
     coord lnd_y;		/* y location in abs coords */
     signed char lnd_type;	/* index in lchr[] */
diff --git a/include/loan.h b/include/loan.h
index 21c60b13..f2ec2c08 100644
--- a/include/loan.h
+++ b/include/loan.h
@@ -41,9 +41,11 @@
 #define SECS_PER_DAY	(60*60*24)
 
 struct lonstr {
+    /* initial part must match struct empobj */
     short ef_type;
-    natid l_loner;		/* loan shark */
     short l_uid;
+    /* end of part matching struct empobj */
+    natid l_loner;		/* loan shark */
     natid l_lonee;		/* sucker */
     signed char l_status;	/* loan status */
     short l_sell;		/* pointer to trade file (unused) */
diff --git a/include/lost.h b/include/lost.h
index acfae5c9..a377c6ec 100644
--- a/include/lost.h
+++ b/include/lost.h
@@ -40,9 +40,9 @@
 struct loststr {
     /* initial part must match struct empobj */
     short ef_type;
+    int lost_uid;		/* lost ID (assigned, otherwise unused) */
     natid lost_owner;		/* Who lost it */
     /* end of part matching struct empobj */
-    int lost_uid;		/* lost ID (assigned, otherwise unused) */
     short lost_type;		/* Type of thing (ship, plane, nuke, land, sector) */
     short lost_id;		/* ID of lost thing */
     coord lost_x;
diff --git a/include/nat.h b/include/nat.h
index c7cb0173..b54c8bf9 100644
--- a/include/nat.h
+++ b/include/nat.h
@@ -69,9 +69,9 @@ typedef enum {
 struct realmstr {
     /* initial part must match struct empobj */
     short ef_type;
+    short r_uid;		/* realm table index */
     natid r_cnum;		/* country number */
     /* end of part matching struct empobj */
-    short r_uid;		/* realm table index */
     unsigned short r_realm;	/* realm number */
     short r_xl, r_xh;		/* horizontal bounds */
     short r_yl, r_yh;		/* vertical bounds */
@@ -81,6 +81,7 @@ struct realmstr {
 struct natstr {
     /* initial part must match struct empobj */
     short ef_type;
+    short nat_uid;		/* equals nat_cnum */
     natid nat_cnum;		/* our country number */
     /* end of part matching struct empobj */
     nat_status nat_stat;
diff --git a/include/news.h b/include/news.h
index 888c78d4..cc182a91 100644
--- a/include/news.h
+++ b/include/news.h
@@ -45,9 +45,11 @@
 #include "nsc.h"
 
 struct nwsstr {
+    /* initial part must match struct empobj */
     short ef_type;
-    natid nws_ano;		/* "actor" country # */
     short nws_uid;		/* unused */
+    /* end of part matching struct empobj */
+    natid nws_ano;		/* "actor" country # */
     signed char nws_vrb;	/* action (verb) */
     natid nws_vno;		/* "victim" country # */
     signed char nws_ntm;	/* number of times */
diff --git a/include/nuke.h b/include/nuke.h
index 3c42a4e9..cc90de95 100644
--- a/include/nuke.h
+++ b/include/nuke.h
@@ -43,8 +43,8 @@
 struct nukstr {
     /* initial part must match struct empobj */
     short ef_type;
-    natid nuk_own;
     short nuk_uid;
+    natid nuk_own;
     coord nuk_x, nuk_y;		/* current loc of device */
     signed char nuk_type;	/* index in nchr[] */
     signed char nuk_effic;	/* unused, always 100% */
diff --git a/include/plane.h b/include/plane.h
index 25c6fd0e..f072ba78 100644
--- a/include/plane.h
+++ b/include/plane.h
@@ -46,8 +46,8 @@
 struct plnstr {
     /* initial part must match struct empobj */
     short ef_type;
-    natid pln_own;		/* owning country */
     short pln_uid;		/* plane unit id */
+    natid pln_own;		/* owning country */
     coord pln_x;		/* plane x-y */
     coord pln_y;
     signed char pln_type;	/* index in plchr[] */
diff --git a/include/sect.h b/include/sect.h
index a960706e..8d9f9d4e 100644
--- a/include/sect.h
+++ b/include/sect.h
@@ -44,8 +44,8 @@
 struct sctstr {
     /* initial part must match struct empobj */
     short ef_type;
+    short sct_uid;		/* equals sctoff(sct_x, sct_y) */
     natid sct_own;		/* owner's country num */
-    short sct_elev;		/* elevation/depth */
     coord sct_x;		/* x coord of sector */
     coord sct_y;		/* y coord of sector */
     signed char sct_type;	/* sector type */
@@ -62,7 +62,7 @@ struct sctstr {
     coord sct_dist_y;
     short sct_avail;		/* available workforce for "other things" */
     short sct_flags;		/* temporary flags */
-    short sct_fill;		/* gunk */
+    short sct_elev;		/* elevation/depth */
     unsigned char sct_work;	/* pct of civ actually working */
     unsigned char sct_coastal;	/* is this a coastal sector? */
     signed char sct_newtype;	/* for changing designations */
diff --git a/include/ship.h b/include/ship.h
index 65097564..cbfed235 100644
--- a/include/ship.h
+++ b/include/ship.h
@@ -63,8 +63,8 @@
 struct shpstr {
     /* initial part must match struct empobj */
     short ef_type;
-    natid shp_own;		/* owner's country num */
     short shp_uid;		/* unit id (ship #) */
+    natid shp_own;		/* owner's country num */
     coord shp_x;		/* x location in abs coords */
     coord shp_y;		/* y location in abs coords */
     signed char shp_type;	/* index in mchr[] */
diff --git a/include/trade.h b/include/trade.h
index 45b4dfe0..8db1e6fe 100644
--- a/include/trade.h
+++ b/include/trade.h
@@ -43,8 +43,8 @@
 struct trdstr {
     /* initial part must match struct empobj */
     short ef_type;
-    natid trd_owner;
     short trd_uid;
+    natid trd_owner;
     /* end of part matching struct empobj */
     short trd_type;
     short trd_unitid;
diff --git a/include/treaty.h b/include/treaty.h
index ba072745..a8c5d258 100644
--- a/include/treaty.h
+++ b/include/treaty.h
@@ -38,9 +38,11 @@
 #include "types.h"
 
 struct trtstr {
+    /* initial part must match struct empobj */
     short ef_type;
-    natid trt_cna;		/* proposer */
     short trt_uid;
+    /* end of part matching struct empobj */
+    natid trt_cna;		/* proposer */
     natid trt_cnb;		/* acceptor */
     signed char trt_status;	/* treaty status */
     char trt_fill;
diff --git a/src/lib/commands/edit.c b/src/lib/commands/edit.c
index b15f8e01..6e678c80 100644
--- a/src/lib/commands/edit.c
+++ b/src/lib/commands/edit.c
@@ -593,6 +593,7 @@ doland(char op, int arg, char *p, struct sctstr *sect)
 	    return RET_SYN;
 	sect->sct_x = newx;
 	sect->sct_y = newy;
+	sect->sct_uid = XYOFFSET(newx, newy);
 	break;
     case 'D':
 	if (!sarg_xy(p, &newx, &newy))
diff --git a/src/lib/commands/swap.c b/src/lib/commands/swap.c
index 6c8fd307..a28b8991 100644
--- a/src/lib/commands/swap.c
+++ b/src/lib/commands/swap.c
@@ -63,12 +63,14 @@ swaps(void)
     /* change the location of secta to that of sectb */
     secta.sct_x = sectb.sct_x;
     secta.sct_y = sectb.sct_y;
+    secta.sct_uid = sectb.sct_uid;
     secta.sct_dist_x = sectb.sct_x;
     secta.sct_dist_y = sectb.sct_y;
     secta.sct_coastal = sectb.sct_coastal;
     /* change the location of sectb to where secta was */
     sectb.sct_x = tmp.sct_x;
     sectb.sct_y = tmp.sct_y;
+    sectb.sct_uid = tmp.sct_uid;
     sectb.sct_dist_x = tmp.sct_x;
     sectb.sct_dist_y = tmp.sct_y;
     sectb.sct_coastal = tmp.sct_coastal;
diff --git a/src/lib/global/nsc.c b/src/lib/global/nsc.c
index b23987e3..b463e049 100644
--- a/src/lib/global/nsc.c
+++ b/src/lib/global/nsc.c
@@ -103,9 +103,10 @@ struct castr pchr_ca[] = {
 };
 
 struct castr sect_ca[] = {
-    /* uid is encoded in x, y */
+    /* uid needs to be NSC_DEITY because it discloses true origin */
+    {NSC_SHORT, NSC_DEITY | NSC_EXTRA, 0, fldoff(sctstr, sct_uid), "uid",
+     EF_SECTOR},
     {NSC_NATID, 0, 0, fldoff(sctstr, sct_own), "owner", EF_NATION},
-    {NSC_SHORT, NSC_DEITY, 0, fldoff(sctstr, sct_elev), "elev", EF_BAD},
     {NSC_XCOORD, NSC_CONST, 0, fldoff(sctstr, sct_x), "xloc", EF_BAD},
     {NSC_YCOORD, NSC_CONST, 0, fldoff(sctstr, sct_y), "yloc", EF_BAD},
     {NSC_CHAR, 0, 0, fldoff(sctstr, sct_type), "des", EF_SECTOR_CHR},
@@ -121,6 +122,7 @@ struct castr sect_ca[] = {
     {NSC_XCOORD, 0, 0, fldoff(sctstr, sct_dist_x), "xdist", EF_BAD},
     {NSC_YCOORD, 0, 0, fldoff(sctstr, sct_dist_y), "ydist", EF_BAD},
     {NSC_SHORT, 0, 0, fldoff(sctstr, sct_avail), "avail", EF_BAD},
+    {NSC_SHORT, NSC_DEITY, 0, fldoff(sctstr, sct_elev), "elev", EF_BAD},
     {NSC_UCHAR, 0, 0, fldoff(sctstr, sct_work), "work", EF_BAD},
     {NSC_UCHAR, 0, 0, fldoff(sctstr, sct_coastal), "coastal", EF_BAD},
     {NSC_CHAR, 0, 0, fldoff(sctstr, sct_newtype), "newdes", EF_SECTOR_CHR},
diff --git a/src/util/fairland.c b/src/util/fairland.c
index 104aa9df..4598eba6 100644
--- a/src/util/fairland.c
+++ b/src/util/fairland.c
@@ -1214,6 +1214,7 @@ static void
 fl_sct_init(coord x, coord y, struct sctstr *sp)
 {
     sp->ef_type = EF_SECTOR;
+    sp->sct_uid = XYOFFSET(x, y);
     sp->sct_x = x;
     sp->sct_y = y;
     sp->sct_dist_x = x;
diff --git a/src/util/files.c b/src/util/files.c
index 2d8c9371..4618ba6e 100644
--- a/src/util/files.c
+++ b/src/util/files.c
@@ -154,7 +154,7 @@ main(int argc, char *argv[])
     memset(&nat, 0, sizeof(nat));
     for (i = 1; i < MAXNOC; i++) {
 	nat.ef_type = EF_NATION;
-	nat.nat_cnum = i;
+	nat.nat_cnum = nat.nat_uid = i;
 	putnat((&nat));
     }
     memset(&realm, 0, sizeof(realm));
@@ -208,6 +208,7 @@ file_sct_init(coord x, coord y, struct sctstr *ptr)
     struct sctstr *sp = (struct sctstr *)ptr;
 
     sp->ef_type = EF_SECTOR;
+    sp->sct_uid = XYOFFSET(x, y);
     sp->sct_x = x;
     sp->sct_y = y;
     sp->sct_dist_x = x;