diff --git a/doc/Guidebook.mn b/doc/Guidebook.mn
index aa3c5dc2e..212f90d9f 100644
--- a/doc/Guidebook.mn
+++ b/doc/Guidebook.mn
@@ -47,7 +47,7 @@
 .ds f0 \*(vr
 .ds f1 \" empty
 .\"DO NOT REMOVE NH_DATESUB .ds f2 Date(%B %-d, %Y)
-.ds f2 December 03, 2025
+.ds f2 December 11, 2025
 .
 .\" A note on some special characters:
 .\" \(lq = left double quote
@@ -3537,7 +3537,7 @@ is a section marker (the closing \(oq\f(CR]\fP\(cq can be followed
 by whitespace and then an arbitrary comment beginning with \(oq\f(CR#\fP\(cq).
 The text between the square brackets is the section name.
 Section markers are only valid after a CHOOSE directive and their names
-are case insensitive.
+are case-insensitive.
 Lines after a section marker belong to that section up until another
 section starts or a marker without a name is encountered or the file ends.
 Lines within sections are ignored unless a CHOOSE directive has selected
@@ -4671,7 +4671,7 @@ or you are making screenshots or streaming video.
 Using the
 .op statuslines:3
 option is recommended so that there will be more room available for
-status information, unless you're using nethack's \fIQt\fP interface
+status information, unless you're using NetHack's \fIQt\fP interface
 or your terminal emulator window displays fewer than 25 lines.
 Persistent.
 .lp "silent  "
diff --git a/doc/Guidebook.tex b/doc/Guidebook.tex
index bdc21ecc6..6c83cd3fd 100644
--- a/doc/Guidebook.tex
+++ b/doc/Guidebook.tex
@@ -48,7 +48,7 @@
 \author{Original version - Eric S. Raymond\\
 (Edited and expanded for 3.7.0 by Mike Stephenson and others)}
 %DO NOT REMOVE NH_DATESUB \date{Date(%B %-d, %Y)}
-\date{December 03, 2025}
+\date{December 11, 2025}
 
 \maketitle
 
@@ -3855,7 +3855,7 @@ is a section marker (the closing `{\tt \verb+]+}' can be followed
 by whitespace and then an arbitrary comment beginning with `{\tt \#}').
 The text between the square brackets is the section name.
 Section markers are only valid after a CHOOSE directive and their names
-are case insensitive.
+are case-insensitive.
 Lines after a section marker belong to that section up until another
 section starts or a marker without a name is encountered or the file ends.
 Lines within sections are ignored unless a CHOOSE directive has selected
@@ -5114,7 +5114,7 @@ or you are making screenshots or streaming video.
 Using the
 {\it statuslines:3\/}
 option is recommended so that there will be more room available for
-status information, unless you're using nethack's {\it Qt\/} interface
+status information, unless you're using NetHack's {\it Qt\/} interface
 or your terminal emulator window displays fewer than 25 lines.
 Persistent.
 %.lp
diff --git a/include/config.h b/include/config.h
index 7069b268d..5016c6702 100644
--- a/include/config.h
+++ b/include/config.h
@@ -149,10 +149,11 @@
 
 #ifdef X11_GRAPHICS
 /*
- * There are two ways that X11 tiles may be defined.  (1) using a custom
- * format loaded by NetHack code, or (2) using the XPM format loaded by
- * the free XPM library.  The second option allows you to then use other
- * programs to generate tiles files.  For example, the PBMPlus tools
+ * There are two ways that X11 tiles may be defined:
+ * (1) using a custom format loaded by NetHack code.
+ * (2) using the XPM format loaded by the free XPM library.
+ * The second option allows you to then use other programs to
+ * generate tiles files.  For example, the PBMPlus tools
  * would allow:
  *  xpmtoppm <x11tiles.xpm | pnmscale 1.25 | ppmquant 90 | \
  *      ppmtoxpm >x11tiles_big.xpm
diff --git a/include/dgn_file.h b/include/dgn_file.h
index 106de5655..4a94e0cdc 100644
--- a/include/dgn_file.h
+++ b/include/dgn_file.h
@@ -43,7 +43,7 @@ struct tmpbranch {
 };
 
 /*
- *    Values for type for tmpbranch structure.
+ *    Values for type in tmpbranch structure.
  */
 #define TBR_STAIR 0   /* connection with both ends having a staircase */
 #define TBR_NO_UP 1   /* connection with no up staircase */
diff --git a/include/dungeon.h b/include/dungeon.h
index d4a1dcf62..f364bcd8e 100644
--- a/include/dungeon.h
+++ b/include/dungeon.h
@@ -169,7 +169,7 @@ struct linfo {
 /* 0x02 was FORGOTTEN, when amnesia made you forget maps */
 #define LFILE_EXISTS 0x04 /* a level file exists for this level */
         /* Note:  VISITED and LFILE_EXISTS are currently almost always
-         * set at the same time.  However they _mean_ different things.
+         * set at the same time.  However, they _mean_ different things.
          */
 };
 
diff --git a/include/flag.h b/include/flag.h
index a566c04de..59ef02c04 100644
--- a/include/flag.h
+++ b/include/flag.h
@@ -482,7 +482,7 @@ struct instance_flags {
 };
 
 /*
- * Old deprecated names
+ * Old, deprecated names
  */
 #ifdef TTY_GRAPHICS
 #define eight_bit_tty wc_eight_bit_input
diff --git a/include/hack.h b/include/hack.h
index 7163bf6a4..a52258a4e 100644
--- a/include/hack.h
+++ b/include/hack.h
@@ -781,7 +781,7 @@ struct selectionvar {
 
 /* structure for 'program_state'; not saved and restored */
 struct sinfo {
-    int gameover;               /* self explanatory? */
+    int gameover;               /* self-explanatory? */
     int stopprint;              /* inhibit further end of game disclosure */
 #ifdef HANGUPHANDLING
     volatile int done_hup;      /* SIGHUP or moral equivalent received
@@ -1350,7 +1350,7 @@ typedef uint32_t mmflags_nht;     /* makemon MM_ flags */
 
 /* Macros for launching objects */
 #define ROLL 0x01          /* the object is rolling */
-#define FLING 0x02         /* the object is flying thru the air */
+#define FLING 0x02         /* the object is flying through the air */
 #define LAUNCH_UNSEEN 0x40 /* hero neither caused nor saw it */
 #define LAUNCH_KNOWN 0x80  /* the hero caused this by explicit action */
 
diff --git a/include/mfndpos.h b/include/mfndpos.h
index 9e560a311..a1ec75461 100644
--- a/include/mfndpos.h
+++ b/include/mfndpos.h
@@ -18,9 +18,9 @@
 #define UNLOCKDOOR  0x00800000L  /* unlocks locked doors */
 #define BUSTDOOR    0x01000000L  /* breaks any doors */
 #define ALLOW_ROCK  0x02000000L  /* pushes rocks */
-#define ALLOW_WALL  0x04000000L  /* walks thru walls */
+#define ALLOW_WALL  0x04000000L  /* walks through walls */
 #define ALLOW_DIG   0x08000000L  /* digs */
-#define ALLOW_BARS  0x10000000L  /* may pass thru iron bars */
+#define ALLOW_BARS  0x10000000L  /* may pass through iron bars */
 #define ALLOW_SANCT 0x20000000L  /* enters temples */
 #define ALLOW_SSM   0x40000000L  /* ignores scare monster */
 #ifdef NHSTDC
diff --git a/include/monattk.h b/include/monattk.h
index 04fbef021..912d93284 100644
--- a/include/monattk.h
+++ b/include/monattk.h
@@ -53,7 +53,7 @@
 #define AD_BLND 11  /* blinds (yellow light) */
 #define AD_STUN 12  /* stuns */
 #define AD_SLOW 13  /* slows */
-#define AD_PLYS 14  /* paralyses */
+#define AD_PLYS 14  /* paralyzes */
 #define AD_DRLI 15  /* drains life levels (Vampire) */
 #define AD_DREN 16  /* drains magic energy */
 #define AD_LEGS 17  /* damages legs (xan) */
@@ -101,7 +101,7 @@ struct mhitm_data {
 };
 
 /*
- *  Monster to monster attacks.  When a monster attacks another (mattackm),
+ *  Monster-to-monster attacks.  When a monster attacks another (mattackm),
  *  any or all of the following can be returned.  See mattackm() for more
  *  details.
  */
diff --git a/include/mondata.h b/include/mondata.h
index 80a177f76..430b5e83d 100644
--- a/include/mondata.h
+++ b/include/mondata.h
@@ -173,7 +173,7 @@
    as unique even though they really aren't; that's ok here */
 #define unique_corpstat(ptr) (((ptr)->geno & G_UNIQ) != 0)
 
-/* this returns the light's range, or 0 if none; if we add more light emitting
+/* this returns the light's range, or 0 if none; if we add more light-emitting
    monsters, we'll likely have to add a new light range field to mons[] */
 #define emits_light(ptr)                                          \
     (((ptr)->mlet == S_LIGHT || (ptr) == &mons[PM_FLAMING_SPHERE] \
diff --git a/include/monflag.h b/include/monflag.h
index 43400fea9..18c2e4256 100644
--- a/include/monflag.h
+++ b/include/monflag.h
@@ -85,9 +85,9 @@ enum ms_sounds {
 #define M1_FLY          0x00000001L /* can fly or float */
 #define M1_SWIM         0x00000002L /* can traverse water */
 #define M1_AMORPHOUS    0x00000004L /* can flow under doors */
-#define M1_WALLWALK     0x00000008L /* can phase thru rock */
+#define M1_WALLWALK     0x00000008L /* can phase through rock */
 #define M1_CLING        0x00000010L /* can cling to ceiling */
-#define M1_TUNNEL       0x00000020L /* can tunnel thru rock */
+#define M1_TUNNEL       0x00000020L /* can tunnel through rock */
 #define M1_NEEDPICK     0x00000040L /* needs pick to tunnel */
 #define M1_CONCEAL      0x00000080L /* hides under objects */
 #define M1_HIDE         0x00000100L /* mimics, blends in with ceiling */
diff --git a/include/objclass.h b/include/objclass.h
index b3da30b49..b04fa496a 100644
--- a/include/objclass.h
+++ b/include/objclass.h
@@ -146,7 +146,7 @@ enum objclass_syms {
 /* for mkobj() use ONLY! odd '-SPBOOK_CLASS' is in case of unsigned enums */
 #define SPBOOK_no_NOVEL (0 - (int) SPBOOK_CLASS)
 
-#define BURNING_OIL (MAXOCLASSES + 1) /* Can be used as input to explode.   */
+#define BURNING_OIL (MAXOCLASSES + 1) /* Can be used as input to explode    */
 #define MON_EXPLODE (MAXOCLASSES + 2) /* Exploding monster (e.g. gas spore) */
 #define TRAP_EXPLODE (MAXOCLASSES + 3)
 
diff --git a/include/quest.h b/include/quest.h
index 28d5ebeb1..77af3049f 100644
--- a/include/quest.h
+++ b/include/quest.h
@@ -14,7 +14,7 @@ struct q_score {              /* Quest "scorecard" */
     Bitfield(killed_leader, 1); /* killed the quest leader */
 
     Bitfield(first_locate, 1); /* only set the first time */
-    Bitfield(met_intermed, 1); /* used if the locate is a person. */
+    Bitfield(met_intermed, 1); /* used if the locate is a person */
     Bitfield(got_final, 1);    /* got the final quest assignment */
 
     Bitfield(made_goal, 3);      /* # of times on goal level */
diff --git a/include/region.h b/include/region.h
index c712173c1..b9b7ced43 100644
--- a/include/region.h
+++ b/include/region.h
@@ -56,7 +56,7 @@ typedef struct {
 
     /* Should probably do the same thing about objects */
 
-    boolean visible;       /* Is the region visible ? */
+    boolean visible;       /* Is the region visible? */
     int glyph;             /* Which glyph to use if visible */
     anything arg;          /* Optional user argument (Ex: strength of
                             * force field, damage of a fire zone, ...*/
diff --git a/include/rm.h b/include/rm.h
index 8ff3c3cea..1c9f49f14 100644
--- a/include/rm.h
+++ b/include/rm.h
@@ -12,8 +12,8 @@
  * building on Don G Kneller's MS-DOS implementation. See drawing.c for
  * the code that permits the user to set the contents of the symbol structure.
  *
- * The door representation was changed by Ari
- * Huttunen(ahuttune@niksula.hut.fi)
+ * The door representation was changed by
+ * Ari Huttunen(ahuttune@niksula.hut.fi).
  */
 
 /*
diff --git a/include/trap.h b/include/trap.h
index a0592f7e1..206951baa 100644
--- a/include/trap.h
+++ b/include/trap.h
@@ -26,7 +26,7 @@ struct trap {
     Bitfield(once, 1);
     Bitfield(madeby_u, 1); /* So monsters may take offence when you trap
                             * them.  Recognizing who made the trap isn't
-                            * completely unreasonable, everybody has
+                            * completely unreasonable; everybody has
                             * their own style.  This flag is also needed
                             * when you untrap a monster.  It would be too
                             * easy to make a monster peaceful if you could
diff --git a/src/hacklib.c b/src/hacklib.c
index 209982751..50be4169b 100644
--- a/src/hacklib.c
+++ b/src/hacklib.c
@@ -711,7 +711,7 @@ online2(coordxy x0, coordxy y0, coordxy x1, coordxy y1)
 }
 
 #ifndef STRNCMPI
-/* case insensitive counted string comparison */
+/* case-insensitive counted string comparison */
 /*{ aka strncasecmp }*/
 int
 strncmpi(
@@ -735,7 +735,7 @@ strncmpi(
 #endif /* STRNCMPI */
 
 #ifndef STRSTRI
-/* case insensitive substring search */
+/* case-insensitive substring search */
 char *
 strstri(const char *str, const char *sub)
 {