diff --git a/cmwind/CMWcmmnds.c b/cmwind/CMWcmmnds.c
index 19357287..7a788d10 100644
--- a/cmwind/CMWcmmnds.c
+++ b/cmwind/CMWcmmnds.c
@@ -302,7 +302,7 @@ cmwPushbutton(
     TxCommand *cmd)
 {
     int button;
-    static char *cmwButton[] = {"left", "middle", "right", NULL};
+    static const char * const cmwButton[] = {"left", "middle", "right", NULL};
 
     if (cmd->tx_argc != 2)
     {
diff --git a/commands/CmdAB.c b/commands/CmdAB.c
index eb5ee4ad..4bed2eee 100644
--- a/commands/CmdAB.c
+++ b/commands/CmdAB.c
@@ -134,7 +134,7 @@ CmdArray(
     MagWindow *w,
     TxCommand *cmd)
 {
-    static char *cmdArrayOption[] = {
+    static const char * const cmdArrayOption[] = {
 	"count 		[[xlo] xhi [ylo] yhi]	array subcells",
 	"width 		[value]			set or return array x-spacing",
 	"height 	[value]			set or return array y-spacing",
@@ -144,7 +144,7 @@ CmdArray(
 	NULL
     };
 
-    char **msg;
+    const char * const *msg;
     int option, locargc, argstart;
     bool doList = FALSE;
     ArrayInfo a;
@@ -597,7 +597,7 @@ CmdBox(
     MagWindow *w,
     TxCommand *cmd)
 {
-    static char *cmdBoxOption[] = {
+    static const char * const cmdBoxOption[] = {
 	"width		[value]			set or return box width",
 	"height		[value]			set or return box height",
 	"size		[width height]		set or return box size",
@@ -626,7 +626,7 @@ CmdBox(
     bool needBox = TRUE;		/* require that box be defined */
     bool refEdit = FALSE;		/* referenced to edit cell coordinates */
     bool cursorRef = FALSE;		/* reference position is the cursor */
-    char **msg;
+    const char * const *msg;
 
     argc = cmd->tx_argc;
     if (argc > 7) goto badusage;
diff --git a/commands/CmdCD.c b/commands/CmdCD.c
index 442a2542..b82caec1 100644
--- a/commands/CmdCD.c
+++ b/commands/CmdCD.c
@@ -130,7 +130,8 @@ CmdCalma(
     TxCommand *cmd)
 {
     int option, ext, value;
-    char **msg, *namep, *dotptr;
+    const char * const *msg;
+    char *namep, *dotptr;
     char writeMode[3];
     CellDef *rootDef;
     FILETYPE f;
@@ -139,14 +140,14 @@ CmdCalma(
     gzFile fz;
 #endif
 
-    static char *gdsExts[] = {".gds", ".gds.gz", ".gds2", ".strm", "", NULL};
-    static char *cmdCalmaYesNo[] = {
+    static const char * const gdsExts[] = {".gds", ".gds.gz", ".gds2", ".strm", "", NULL};
+    static const char * const cmdCalmaYesNo[] = {
 		"no", "false", "off", "0", "yes", "true", "on", "1", 0 };
-    static char *cmdCalmaAllowDisallow[] = {"disallow", "0", "allow", "1", 0};
-    static char *cmdCalmaPolygonType[] = {"none", "temporary", "keep", 0};
-    static char *cmdCalmaWarnOptions[] = { "default", "none", "align",
+    static const char * const cmdCalmaAllowDisallow[] = {"disallow", "0", "allow", "1", 0};
+    static const char * const cmdCalmaPolygonType[] = {"none", "temporary", "keep", 0};
+    static const char * const cmdCalmaWarnOptions[] = { "default", "none", "align",
 		"limit", "redirect", "help", 0 };
-    static char *cmdCalmaOption[] =
+    static const char * const cmdCalmaOption[] =
     {
 	"help		print this help information",
 	"abstract [allow|disallow]\n"
@@ -1115,7 +1116,7 @@ CmdCellname(
     void (*func)();
     CellDef *newDef, *cellDef;
 
-    static char *cmdCellOption[] =
+    static const char * const cmdCellOption[] =
     {
 	"children 	list children of selected or named cell",
 	"parents 	list parents of selected or named cell",
@@ -1151,7 +1152,7 @@ CmdCellname(
 		   IDX_ORIENTATION, IDX_RENAME, IDX_READWRITE,
 		   IDX_MODIFIED } optionType;
 
-    static char *cmdCellnameYesNo[] = {
+    static const char * const cmdCellnameYesNo[] = {
 		"no", "false", "off", "0", "yes", "true", "on", "1", 0 };
 
     if (strstr(cmd->tx_argv[0], "in"))
@@ -1720,7 +1721,8 @@ CmdCif(
     TxCommand *cmd)
 {
     int option, yesno;
-    char **msg, *namep;
+    const char * const *msg;
+    char *namep;
     CellDef *rootDef, *paintDef;
     Rect box;
     TileType layer;
@@ -1735,11 +1737,11 @@ CmdCif(
     int argshift;
     char **argv = cmd->tx_argv;
 
-    static char *cmdCifWarnOptions[] = { "default", "none", "align",
+    static const char * const cmdCifWarnOptions[] = { "default", "none", "align",
 		"limit", "redirect", "help", 0 };
-    static char *cmdCifYesNo[] = { "no", "yes", 0 };
-    static char *cmdCifInOut[] = { "input", "output", 0 };
-    static char *cmdCifOption[] =
+    static const char * const cmdCifYesNo[] = { "no", "yes", 0 };
+    static const char * const cmdCifInOut[] = { "input", "output", 0 };
+    static const char * const cmdCifOption[] =
     {
 	"*array layer		display CIF layer under box (array only)",
 	"*hier layer		display CIF layer under box (hier only)",
@@ -3692,7 +3694,7 @@ CmdCrash(
 {
     int option = -1;
     char *filename = NULL;
-    static char *cmdCrashOpt[] = {"save", "recover", 0};
+    static const char * const cmdCrashOpt[] = {"save", "recover", 0};
 
     if (cmd->tx_argc > 3)
 	TxError("Usage: %s save|recover [filename]\n", cmd->tx_argv[0]);
@@ -4000,7 +4002,7 @@ CmdDrc(
     CellDef	* rootDef;
     Transform	  trans;
     MagWindow	* window;
-    char 	**msg;
+    const char 	* const *msg;
     bool	wizardHelp;
     bool	incremental;
     bool	doforall = FALSE;
@@ -4016,7 +4018,7 @@ CmdDrc(
     Tcl_Obj *lobj;
 #endif
 
-    static char *cmdDrcOption[] =
+    static const char * const cmdDrcOption[] =
     {
 	"*flatcheck             check box area by flattening",
 	"*halo [d]		limit error checking to areas of d units",
@@ -4971,10 +4973,10 @@ cmdDumpParseArgs(
     hasChild = hasRoot = hasTrans = FALSE;
     while (ac > 0)
     {
-	static char *kwdNames[] = { "child", "parent", "0", "90", "180", "270",
+	static const char * const kwdNames[] = { "child", "parent", "0", "90", "180", "270",
 					    "v", "0v", "90v", "180v", "270v",
 					    "h", "0h", "90h", "180h", "270h", 0 };
-	static char *refPointNames[] = { "ll", "lr", "ul", "ur", 0 };
+	static const char * const refPointNames[] = { "ll", "lr", "ul", "ur", 0 };
 	Label *lab;
 	int n,p;
 
diff --git a/commands/CmdE.c b/commands/CmdE.c
index 0c42c745..1a43e2c2 100644
--- a/commands/CmdE.c
+++ b/commands/CmdE.c
@@ -311,14 +311,14 @@ CmdElement(
 {
 
     int option, type;
-    char **msg;
+    const char * const *msg;
     Rect area;
     int style;
     CellDef *def;
     CellUse *use;
     bool getopt;
 
-    static char *cmdElementOption[] = {
+    static const char * const cmdElementOption[] = {
 	"add			create a new element",
 	"delete		delete an existing element",
 	"configure		configure or query an existing element",
@@ -328,14 +328,14 @@ CmdElement(
 	NULL
     };
 
-    static char *cmdElementType[] = {
+    static const char * const cmdElementType[] = {
 	"line		name style x1 y1 x2 y2",
 	"rectangle		name style llx lly urx ury",
 	"text		name style cx cy label",
 	NULL
     };
 
-    static char *cmdConfigureType[] = {
+    static const char * const cmdConfigureType[] = {
 	"text		get (or) replace <string>",
 	"style		get (or) add <style> (or) remove <style>",
 	"position		get (or) <point> (or) <rect>",
@@ -945,7 +945,8 @@ CmdExtract(
     MagWindow *w,
     TxCommand *cmd)
 {
-    char **msg, *namep, *arg;
+    const char * const *msg;
+    char *namep, *arg;
     int option, warn, len, n, all;
     int dist;
     bool no;
@@ -957,7 +958,7 @@ CmdExtract(
     int argc = cmd->tx_argc;
     char **argv = cmd->tx_argv;
 
-    static char *cmdExtWarn[] =
+    static const char * const cmdExtWarn[] =
     {
 	"all			enable all warnings",
 	"dup			warn when different nodes have the same name",
@@ -965,7 +966,7 @@ CmdExtract(
 	"labels		warn when subcell nodes are unlabelled",
 	NULL
     };
-    static char *cmdExtOption[] =
+    static const char * const cmdExtOption[] =
     {
 	"adjust			compensate R and C hierarchically",
 	"all			all options",
@@ -978,7 +979,7 @@ CmdExtract(
 	"aliases		output all net name aliases",
 	NULL
     };
-    static char *cmdExtLength[] =
+    static const char * const cmdExtLength[] =
     {
 	"clear			clear the driver and receiver tables",
 	"driver termName(s)	identify a driving (output) terminal",
@@ -988,7 +989,7 @@ CmdExtract(
 
     /* These must match definitions EXT_UNIQ_* in extract/extract.h: */
 
-    static char *cmdExtUniq[] =
+    static const char * const cmdExtUniq[] =
     {
 	"all			extract matching labels as unique nodes",
 	"#			extract tagged labels as unique nodes",
@@ -996,7 +997,7 @@ CmdExtract(
 	"notopports		ignore top-level ports when making labels unique",
 	NULL
     };
-    static char *cmdExtCmd[] =
+    static const char * const cmdExtCmd[] =
     {
 	"all			extract root cell and all its children",
 	"cell name		extract selected cell into file \"name\"",
diff --git a/commands/CmdFI.c b/commands/CmdFI.c
index 49345ca6..9b6430d2 100644
--- a/commands/CmdFI.c
+++ b/commands/CmdFI.c
@@ -150,7 +150,7 @@ CmdFeedback(
     MagWindow *w,
     TxCommand *cmd)
 {
-    static char *cmdFeedbackOptions[] =
+    static const char * const cmdFeedbackOptions[] =
     {
 	"add text [style] [points...]	create new feedback area over box",
 	"clear [substring]		clear all or selected feedback info",
@@ -161,11 +161,11 @@ CmdFeedback(
 	"why				print all feedback messages under box",
 	NULL
     };
-    static char *cmdFeedbackStyleNames[] =
+    static const char * const cmdFeedbackStyleNames[] =
     {
 	"dotted", "medium", "outline", "pale", "solid", NULL
     };
-    static int cmdFeedbackStyles[] =
+    static const int cmdFeedbackStyles[] =
     {
 	STYLE_DOTTEDHIGHLIGHTS, STYLE_MEDIUMHIGHLIGHTS,
 	STYLE_OUTLINEHIGHLIGHTS, STYLE_PALEHIGHLIGHTS,
@@ -176,7 +176,8 @@ CmdFeedback(
 					 */
     int option, i, style, pstart;
     Rect box, r;
-    char *text, **msg;
+    char *text;
+    const char * const *msg;
     CellDef *rootDef;
     HashTable table;
     HashEntry *h;
@@ -1267,7 +1268,7 @@ CmdGrid(
     int xSpacing, ySpacing, xOrig, yOrig, multiple;
     DBWclientRec *crec;
     char *boxvalues;
-    static char *cmdGridOptions[] =
+    static const char * const cmdGridOptions[] =
     {
 	"box [values]	report the box representing the user grid",
 	"help		print this message",
diff --git a/commands/CmdLQ.c b/commands/CmdLQ.c
index 976fe165..b9f42b29 100644
--- a/commands/CmdLQ.c
+++ b/commands/CmdLQ.c
@@ -408,7 +408,7 @@ CmdLoad(
 
     saveVerbose = DBVerbose;
 
-    static char *cmdLoadOption[] =
+    static const char * const cmdLoadOption[] =
     {
 	"-nowindow	load file but do not display in the layout window",
 	"-dereference	use search paths and ignore embedded cell paths in file",
@@ -600,7 +600,7 @@ CmdLocking(
 {
     int option;
 
-    static char *cmdLockingYesNo[] = { "disable", "no", "false", "off", "0",
+    static const char * const cmdLockingYesNo[] = { "disable", "no", "false", "off", "0",
 	    "enable", "yes", "true", "on", "1", 0 };
 
     if (cmd->tx_argc <= 1)
@@ -1092,7 +1092,7 @@ CmdPath(
     char **pathptr;
     char *srcptr;
     int option;
-    static char *cmdPathOption[] =
+    static const char * const cmdPathOption[] =
     {
 	"search	[[+]path]	set [append to] search path",
 	"cell	[[+]path]	set [append to] cell path",
@@ -1522,7 +1522,7 @@ CmdPort(
     MagWindow *w,
     TxCommand *cmd)
 {
-    char **msg;
+    const char * const *msg;
     int argstart;
     int i, refidx, idx, pos, type, option, argc;
     unsigned int dirmask;
@@ -1532,7 +1532,7 @@ CmdPort(
     Rect editBox, tmpArea;
     CellDef *editDef;
 
-    static char *cmdPortOption[] =
+    static const char * const cmdPortOption[] =
     {
 	"class	[type]		get [set] port class type",
 	"use	[type]		get [set] port use type",
@@ -1553,7 +1553,7 @@ CmdPort(
 	NULL
     };
 
-    static char *cmdPortClassTypes[] =
+    static const char * const cmdPortClassTypes[] =
     {
 	"default",
 	"input",
@@ -1578,7 +1578,7 @@ CmdPort(
 	PORT_CLASS_FEEDTHROUGH
     };
 
-    static char *cmdPortUseTypes[] =
+    static const char * const cmdPortUseTypes[] =
     {
 	"default",
 	"analog",
@@ -1601,7 +1601,7 @@ CmdPort(
 	PORT_USE_CLOCK
     };
 
-    static char *cmdPortShapeTypes[] =
+    static const char * const cmdPortShapeTypes[] =
     {
 	"default",
 	"abutment",
@@ -2474,9 +2474,10 @@ CmdNetlist(
     TxCommand *cmd)
 {
     int option;
-    char **msg, *lastargv;
+    const char * const *msg;
+    char *lastargv;
     Point cursor;
-    static char *cmdNetlistOption[] =
+    static const char * const cmdNetlistOption[] =
     {
 	"help           print this help information",
 	"select		select the net nearest the cursor",
@@ -2563,7 +2564,7 @@ CmdOrient(
     CellDef *rootDef;
     bool noAdjust = FALSE;
 
-    static char *orientNames[] = {      "0", "90", "180", "270",
+    static const char * const orientNames[] = {      "0", "90", "180", "270",
                                         "v", "0v", "90v", "180v", "270v",
                                         "h", "0h", "90h", "180h", "270h",
                                         "N", "E", "S", "W",
diff --git a/commands/CmdRS.c b/commands/CmdRS.c
index 449508b2..8c07432f 100644
--- a/commands/CmdRS.c
+++ b/commands/CmdRS.c
@@ -760,7 +760,7 @@ CmdSelect(
      * second table, due to a help message for ":select" with no arguments.
      */
 
-    static char *cmdSelectOption[] =
+    static const char * const cmdSelectOption[] =
     {
 	"area",
 	"visible",
@@ -783,7 +783,7 @@ CmdSelect(
 	"short",
 	NULL
     };
-    static char *cmdSelectMsg[] =
+    static const char * const cmdSelectMsg[] =
     {
 	"[more | less | nocycle] [layers] [at x y]\n"
         "                                [de]select paint chunk/region/net under\n"
@@ -839,7 +839,9 @@ CmdSelect(
 				 * also used to step through multiple uses.
 				 */
     static bool lessCycle = FALSE, lessCellCycle = FALSE;
-    char path[200], *printPath, **msg, **optionArgs, *feedtext, *pstr, *globmatch;
+    char path[200], *printPath;
+    const char * const *msg;
+    char **optionArgs, *feedtext, *pstr, *globmatch;
     TerminalPath tpath;
     CellUse *use;
     CellDef *rootBoxDef;
@@ -2092,7 +2094,7 @@ CmdSetLabel(
 {
     int pos = -1, font = -1, size = 0, rotate = 0, flags = 0;
     int locargc, argstart = 1;
-    char **msg;
+    const char * const *msg;
     Point offset;
     Rect rect;
     TileType ttype;
@@ -2102,10 +2104,10 @@ CmdSetLabel(
     Tcl_Obj *lobj;
 #endif
 
-    static char *cmdLabelYesNo[] = { "no", "false", "off", "0",
+    static const char * const cmdLabelYesNo[] = { "no", "false", "off", "0",
 		"yes", "true", "on", "1", 0 };
 
-    static char *cmdLabelSetOption[] =
+    static const char * const cmdLabelSetOption[] =
     {
 	"box <lx> <ly> <ux> <uy>	change/get label box",
 	"font <name>		change/get label font",
@@ -2847,7 +2849,7 @@ CmdSnap(
     MagWindow *w,
     TxCommand *cmd)
 {
-    static char *names[] = { "off", "internal", "lambda", "grid", "user", "on",
+    static const char * const names[] = { "off", "internal", "lambda", "grid", "user", "on",
 		"list", 0 };
     int n = SNAP_LIST;
     DBWclientRec *crec;
diff --git a/commands/CmdTZ.c b/commands/CmdTZ.c
index 091da4a0..6b5feb9a 100644
--- a/commands/CmdTZ.c
+++ b/commands/CmdTZ.c
@@ -168,16 +168,16 @@ CmdTech(
     TxCommand *cmd)		/* Info about command options. */
 {
     int	option, action, i, locargc;
-    char **msg;
+    const char * const *msg;
 #ifdef MAGIC_WRAPPER
     Tcl_Obj *lobj;
 #endif
     bool noprompt = FALSE;
 
-    static char *actionNames[] =
+    static const char * const actionNames[] =
 	{ "no", "yes", 0 };
 
-    static char *cmdTechOption[] =
+    static const char * const cmdTechOption[] =
     {
 	"load filename [-noprompt][-[no]override]\n\
 				Load a new technology",
@@ -1427,7 +1427,8 @@ CmdWire(
     TxCommand *cmd)
 {
     int option, locargc;
-    char **msg, *lastargv;
+    const char * const *msg;
+    char *lastargv;
     TileType type;
     int width;
 
@@ -1435,7 +1436,7 @@ CmdWire(
     Tcl_Obj *lobj;
 #endif
 
-    static char *cmdWireOption[] =
+    static const char * const cmdWireOption[] =
     {
 	"decrement layer|width 	decrement the wire layer or width",
 	"help                   print this help information",
@@ -1866,7 +1867,7 @@ CmdWriteall(
 {
     int cmdWriteallFunc(CellDef *def, TxCommand *cmd);
     int option = -1;
-    static char *writeallOpts[] = { "force", "modified", 0 };
+    static const char * const writeallOpts[] = { "force", "modified", 0 };
     int argc;
     int flags = CDMODIFIED | CDBOXESCHANGED | CDSTAMPSCHANGED;
 
diff --git a/database/DBtpaint.c b/database/DBtpaint.c
index fe6bdf0a..189a17a5 100644
--- a/database/DBtpaint.c
+++ b/database/DBtpaint.c
@@ -356,9 +356,9 @@ DBTechAddCompose(sectionName, argc, argv)
 {
     TileType type, r, s;
     int pNum, ruleType, i;
-    static char *ruleNames[] =
+    static const char * const ruleNames[] =
 	{ "compose", "decompose", "paint", "erase", 0 };
-    static int ruleTypes[] =
+    static const int ruleTypes[] =
 	{ RULE_COMPOSE, RULE_DECOMPOSE, RULE_PAINT, RULE_ERASE };
 
     if (argc < 4)
diff --git a/dbwind/DBWelement.c b/dbwind/DBWelement.c
index 408be04e..7ca6542a 100644
--- a/dbwind/DBWelement.c
+++ b/dbwind/DBWelement.c
@@ -946,12 +946,12 @@ DBWElementParseFlags(MagWindow *w, char *ename, char *flagstr)
     HashEntry *entry;
     int flidx, newflags;
 
-    static char *lineOffset[] = {"halfx", "halfy", "exactx", "exacty",
+    static const char * const lineOffset[] = {"halfx", "halfy", "exactx", "exacty",
 		"arrowleft", "arrowbottom", "arrowright", "arrowtop",
 		"plainleft", "plainbottom", "plainright", "plaintop", NULL};
-    static char *textSizes[] = {"small", "medium", "large", "xlarge",
+    static const char * const textSizes[] = {"small", "medium", "large", "xlarge",
 	"default", NULL};
-    static char *genFlags[] = {"persistent", "temporary", NULL};
+    static const char * const genFlags[] = {"persistent", "temporary", NULL};
 
     entry = HashFind(&elementTable, ename);
     if (entry == NULL)
diff --git a/drc/DRCtech.c b/drc/DRCtech.c
index 170fb037..995d166b 100644
--- a/drc/DRCtech.c
+++ b/drc/DRCtech.c
@@ -3457,7 +3457,7 @@ drcRectangle(argc, argv)
     int why = drcWhyCreate(argv[4]);
     TileTypeBitMask types, nottypes;
     int maxwidth;
-    static char *drcRectOpt[4] = {"any", "even", "odd", 0};
+    static const char * const drcRectOpt[4] = {"any", "even", "odd", 0};
     int i, j, even, plane;
     PlaneMask pMask, pset, ptest;
 
diff --git a/extflat/EFantenna.c b/extflat/EFantenna.c
index 8e9d965d..a571a6b0 100644
--- a/extflat/EFantenna.c
+++ b/extflat/EFantenna.c
@@ -136,7 +136,7 @@ CmdAntennaCheck(w, cmd)
     int value;
     int argc = cmd->tx_argc;
     char **argv = cmd->tx_argv;
-    char **msg;
+    const char * const *msg;
     bool err_result;
 
     short sd_rclass;
@@ -146,7 +146,7 @@ CmdAntennaCheck(w, cmd)
 
     CellUse *editUse;
 
-    static char *cmdAntennaCheckOption[] = {
+    static const char * const cmdAntennaCheckOption[] = {
 	"[run] [options]	run antennacheck on current cell\n"
 	"			use \"run -help\" to get standard options",
 	"debug			print detailed information about each error",