diff --git a/src/frontend/inpcom.c b/src/frontend/inpcom.c
index ccfa6ea64..413cccff5 100644
--- a/src/frontend/inpcom.c
+++ b/src/frontend/inpcom.c
@@ -2869,8 +2869,10 @@ static char *inp_spawn_brace(char *s)
   removes  " " quotes, returns lower case letters,
   replaces non-printable characters with '_', however if
   non-printable character is the only character in a line,
-  replace it by '*'. If there is a XSPICE code model .model
-  line with file input, keep quotes and case for the file path.
+  replace it by '*'. Leave quotes in .param, .subckt and x
+  (subcircuit instance) cards to allow string-valued parameters.
+  If there is a XSPICE code model .model line with file input,
+  keep quotes and case for the file path.
   *-------------------------------------------------------------------------*/
 
 void inp_casefix(char *string)
@@ -2883,20 +2885,23 @@ void inp_casefix(char *string)
         return;
     }
     if (string) {
+        bool keepquotes;
+
 #ifdef XSPICE
-        /* special treatment of code model file input */
         char* tmpstr = NULL;
-        bool keepquotes = ciprefix(".model", string);
-        if (keepquotes){
+
+        /* Special treatment of code model file input. */
+
+        if (ciprefix(".model", string))
             tmpstr = strstr(string, "file=");
-            keepquotes = keepquotes && tmpstr;
-        }
 #endif
+        keepquotes = ciprefix(".param", string); // Allow string params
+
         while (*string) {
 #ifdef XSPICE
             /* exclude file name inside of quotes from getting lower case,
                keep quotes to enable spaces in file path */
-            if (keepquotes && string == tmpstr) {
+            if (string == tmpstr) {
                 string = string + 6; // past first quote
                 while (*string && *string != '"')
                     string++;
@@ -2907,12 +2912,13 @@ void inp_casefix(char *string)
             }
 #endif
             if (*string == '"') {
-                *string++ = ' ';
+                if (!keepquotes)
+                    *string++ = ' ';
                 while (*string && *string != '"')
                     string++;
                 if (*string == '\0')
                     continue; /* needed if string is "something ! */
-                if (*string == '"')
+                if (*string == '"' && !keepquotes)
                     *string = ' ';
             }
             if (*string && !isspace_c(*string) && !isprint_c(*string))
@@ -5054,24 +5060,40 @@ static int inp_split_multi_param_lines(struct card *card, int line_num)
 
                 char *beg_param, *end_param;
 
-                bool get_expression = FALSE;
-                bool get_paren_expression = FALSE;
+                int expression_depth = 0;
+                int paren_depth = 0;
 
                 beg_param = skip_back_ws(equal_ptr, curr_line);
                 beg_param = skip_back_non_ws(beg_param, curr_line);
                 end_param = skip_ws(equal_ptr + 1);
-                while (*end_param != '\0' &&
-                        (!isspace_c(*end_param) || get_expression ||
-                                get_paren_expression)) {
-                    if (*end_param == '{')
-                        get_expression = TRUE;
-                    if (*end_param == '(')
-                        get_paren_expression = TRUE;
-                    if (*end_param == '}')
-                        get_expression = FALSE;
-                    if (*end_param == ')')
-                        get_paren_expression = FALSE;
-                    end_param++;
+                while (*end_param && !isspace_c(*end_param)) {
+                    /* Advance over numeric or string expression. */
+
+                    if (*end_param == '"') {
+                        /* RHS is quoted string. */
+
+                        end_param++;
+                        while (*end_param != '\0' && *end_param != '"')
+                            end_param++;
+                        if (*end_param == '"')
+                            end_param++;
+                    } else {
+                        while (*end_param != '\0' && *end_param != '"' &&
+                               (!isspace_c(*end_param) ||
+                                expression_depth || paren_depth)) {
+                            if (*end_param == ',' && paren_depth == 0)
+                                break;
+                            if (*end_param == '{')
+                                ++expression_depth;
+                            if (*end_param == '(')
+                                ++paren_depth;
+                            if (*end_param == '}' && expression_depth > 0)
+                                --expression_depth;
+                            if (*end_param == ')' && paren_depth > 0)
+                                --paren_depth;
+                            end_param++;
+                        }
+                    }
                 }
 
                 if (end_param[-1] == ',')
diff --git a/src/frontend/numparam/general.h b/src/frontend/numparam/general.h
index a17c26d9a..a0bf7aeaf 100644
--- a/src/frontend/numparam/general.h
+++ b/src/frontend/numparam/general.h
@@ -9,6 +9,7 @@
 #include "ngspice/bool.h"
 
 
+void pscat(DSTRINGPTR s, const char *str, const char *stop);
 void pscopy(DSTRINGPTR s, const char *str, const char *stop);
 void scopyd(DSTRINGPTR dst, const DSTRINGPTR src);
 void scopys(DSTRINGPTR a, const char *b);
diff --git a/src/frontend/numparam/mystring.c b/src/frontend/numparam/mystring.c
index fe58576e1..c16043877 100644
--- a/src/frontend/numparam/mystring.c
+++ b/src/frontend/numparam/mystring.c
@@ -123,21 +123,26 @@ scopys(DSTRINGPTR s, const char *t)     /* returns success flag */
 }
 
 
-/* Copy until stop char (exclusive) or end of string if none given */
+/* Concatentate until stop char (exclusive) or end of string if none given */
+
 void
-pscopy(DSTRINGPTR dstr_p, const char *t, const char *stop)
+pscat(DSTRINGPTR dstr_p, const char *t, const char *stop)
 {
     if (!stop) { /* locate end of string if no stop char given */
         stop = strchr(t, '\0');
     }
-
-    ds_clear(dstr_p);
     if (ds_cat_mem(dstr_p, t, (size_t) (stop - t)) != DS_E_OK) {
         fprintf(stderr, "Error: DS could not copy partially string %s\n", t);
         controlled_exit(-1);
     }
+} /* end of function pscat */
 
-    return;
+/* Copy until stop char (exclusive) or end of string if none given */
+void
+pscopy(DSTRINGPTR dstr_p, const char *t, const char *stop)
+{
+    ds_clear(dstr_p);
+    pscat(dstr_p, t, stop);
 } /* end of function pscopy */
 
 
diff --git a/src/frontend/numparam/numpaif.h b/src/frontend/numparam/numpaif.h
index 800f4c701..560a70da2 100644
--- a/src/frontend/numparam/numpaif.h
+++ b/src/frontend/numparam/numpaif.h
@@ -18,9 +18,9 @@ extern int    nupa_eval(struct card *card);
 extern void   nupa_signal(int sig);
 extern void   nupa_scan(const struct card *card);
 extern void   nupa_list_params(FILE *cp_out);
-extern double nupa_get_param(char *param_name, int *found);
+extern double nupa_get_param(const char *param_name, int *found);
+extern const char *nupa_get_string_param(const char *param_name);
 extern void   nupa_add_param(char *param_name, double value);
-extern void   nupa_add_inst_param(char *param_name, double value);
 extern void   nupa_copy_inst_dico(void);
 extern void   nupa_del_dicoS(void);
 extern int    nupa_add_dicoslist(void);
diff --git a/src/frontend/numparam/numparam.h b/src/frontend/numparam/numparam.h
index e5076a4c2..a294e2a2e 100644
--- a/src/frontend/numparam/numparam.h
+++ b/src/frontend/numparam/numparam.h
@@ -68,3 +68,4 @@ void nupa_subcktexit(dico_t *);
 entry_t *entrynb(dico_t *dico, char *s);
 entry_t *attrib(dico_t *, NGHASHPTR htable, char *t, char op);
 void del_attrib(void *);
+void nupa_copy_inst_entry(char *param_name, entry_t *proto);
diff --git a/src/frontend/numparam/spicenum.c b/src/frontend/numparam/spicenum.c
index 338e83464..ce1af5153 100644
--- a/src/frontend/numparam/spicenum.c
+++ b/src/frontend/numparam/spicenum.c
@@ -415,6 +415,9 @@ dump_symbol_table(NGHASHPTR htable_p, FILE *fp)
     {
         if (entry->tp == NUPA_REAL)
             fprintf(fp, "       ---> %s = %g\n", entry->symbol, entry->vl);
+        else if (entry->tp == NUPA_STRING)
+            fprintf(fp, "       ---> %s = \"%s\"\n",
+                    entry->symbol, entry->sbbase);
     }
 }
 
@@ -456,8 +459,7 @@ nupa_list_params(FILE *fp)
  * Otherwise, we have to exhaust all of the tables including the global
  * table.
  * ----------------------------------------------------------------- */
-double
-nupa_get_param(char *param_name, int *found)
+static entry_t *nupa_get_entry(const char *param_name)
 {
     dico_t *dico = dicoS;       /* local copy for speed */
     int depth;                  /* nested subcircit depth */
@@ -465,21 +467,40 @@ nupa_get_param(char *param_name, int *found)
     for (depth = dico->stack_depth; depth >= 0; depth--) {
         NGHASHPTR htable_p = dico->symbols[depth];
         if (htable_p) {
-            entry_t *entry = (entry_t *) nghash_find(htable_p, param_name);
-            if (entry) {
-                *found = 1;
-                return entry->vl;
-            }
+            entry_t *entry;
+
+            entry = (entry_t *)nghash_find(htable_p, (void *)param_name);
+            if (entry)
+                return entry;
         }
     }
+    return NULL;
+}
 
+double
+nupa_get_param(const char *param_name, int *found)
+{
+    entry_t *entry = nupa_get_entry(param_name);
+    if (entry && entry->tp == NUPA_REAL) {
+        *found = 1;
+        return entry->vl;
+    }
     *found = 0;
     return 0;
 }
 
+const char *
+nupa_get_string_param(const char *param_name)
+{
+    entry_t *entry = nupa_get_entry(param_name);
+    if (entry && entry->tp == NUPA_STRING)
+        return entry->sbbase;
+    return NULL;
+}
 
-void
-nupa_add_param(char *param_name, double value)
+
+static void
+nupa_copy_entry(entry_t *proto)
 {
     dico_t *dico = dicoS;       /* local copy for speed */
     entry_t *entry;             /* current entry */
@@ -491,18 +512,32 @@ nupa_add_param(char *param_name, double value)
 
     htable_p = dico->symbols[dico->stack_depth];
 
-    entry = attrib(dico, htable_p, param_name, 'N');
+    entry = attrib(dico, htable_p, proto->symbol, 'N');
     if (entry) {
-        entry->vl = value;
-        entry->tp = NUPA_REAL;
-        entry->ivl = 0;
-        entry->sbbase = NULL;
+        entry->vl = proto->vl;
+        entry->tp = proto->tp;
+        entry->ivl = proto->ivl;
+        entry->sbbase = proto->sbbase;
     }
 }
 
 
 void
-nupa_add_inst_param(char *param_name, double value)
+nupa_add_param(char *param_name, double value)
+{
+    entry_t entry;
+
+    entry.symbol = param_name;
+    entry.vl = value;
+    entry.tp = NUPA_REAL;
+    entry.ivl = 0;
+    entry.sbbase = NULL;
+    nupa_copy_entry(&entry);
+}
+
+
+void
+nupa_copy_inst_entry(char *param_name, entry_t *proto)
 {
     dico_t *dico = dicoS;       /* local copy for speed */
     entry_t *entry;             /* current entry */
@@ -512,10 +547,10 @@ nupa_add_inst_param(char *param_name, double value)
 
     entry = attrib(dico, dico->inst_symbols, param_name, 'N');
     if (entry) {
-        entry->vl = value;
-        entry->tp = NUPA_REAL;
-        entry->ivl = 0;
-        entry->sbbase = NULL;
+        entry->vl = proto->vl;
+        entry->tp = proto->tp;
+        entry->ivl = proto->ivl;
+        entry->sbbase = proto->sbbase;
     }
 }
 
@@ -542,7 +577,7 @@ nupa_copy_inst_dico(void)
              entry;
              entry = (entry_t *) nghash_enumerateRE(dico->inst_symbols, &iter))
         {
-            nupa_add_param(entry->symbol, entry->vl);
+            nupa_copy_entry(entry);
             dico_free_entry(entry);
         }
 
diff --git a/src/frontend/numparam/xpressn.c b/src/frontend/numparam/xpressn.c
index 1f523f66c..fd0749bc3 100644
--- a/src/frontend/numparam/xpressn.c
+++ b/src/frontend/numparam/xpressn.c
@@ -232,7 +232,6 @@ message(dico_t *dico, const char *fmt, ...)
                 dico->oldline);
         }
     }
-
     va_start(ap, fmt);
     vfprintf(stderr, fmt, ap);
     va_end(ap);
@@ -275,7 +274,6 @@ dico_free_entry(entry_t *entry)
 {
     if (entry->symbol)
         txfree(entry->symbol);
-
     txfree(entry);
 }
 
@@ -339,7 +337,7 @@ dicostack_pop(dico_t *dico)
                 fprintf(stderr, "Error: DS could not add string %s\n", inst_name);
                 controlled_exit(-1);
             }
-            nupa_add_inst_param(ds_get_buf(&param_name), entry->vl);
+            nupa_copy_inst_entry(ds_get_buf(&param_name), entry);
             dico_free_entry(entry);
         }
         nghash_free(htable_p, NULL, NULL);
@@ -440,6 +438,8 @@ del_attrib(void *entry_p)
     entry_t *entry = (entry_t*) entry_p;
     if(entry) {
         tfree(entry->symbol);
+        if (entry->sbbase)
+            tfree(entry->sbbase);
         tfree(entry);
     }
 }
@@ -1085,6 +1085,79 @@ formula(dico_t *dico, const char *s, const char *s_end, bool *perror)
 }
 
 
+/* Check for a string expression, return end  pointer or NULL.
+ * A string expression is a sequence of quoted strings and string
+ * variables, optionally enclosed by '{}' with no interventing space.
+ * If successful return pointer to next char, otherwise NULL.
+ * Evaluated string is returned in *qstr_p (may be NULL).
+ */
+
+static char *string_expr(dico_t *dico, DSTRINGPTR qstr_p,
+                         const char *t, const char *t_end)
+{
+    const char *tie;
+    bool        ok = FALSE;
+
+    while (isblank(*t) && t < t_end)
+        ++t;
+    if (qstr_p)
+        ds_clear(qstr_p);
+    for (; t < t_end; ) {
+        if (*t == '"') {
+            /* String constant. */
+
+            tie = ++t;
+            while (*t != '"' && t < t_end)
+                ++t;
+            if (qstr_p)
+                pscat(qstr_p, tie, t);
+            if (*t == '"')
+                ++t;
+            ok = TRUE;
+            continue;
+        }
+        if (*t == '{') {
+            /* Isolate and check wrapped identifier. */
+
+            tie = ++t;
+            while (t < t_end) {
+                if (*t == '}')
+                    break;
+                ++t;
+            }
+        } else {
+            /* Last option: naked string-valued param. */
+
+            tie = t;
+            t = fetchid(t, t_end);
+            if (t == tie )
+                return NULL;
+        }
+        /* Now pointers tie, t should bracket an identifier. */
+
+        {
+            DS_CREATE(lcl_str, 200);
+            entry_t    *entry;
+
+            /* Formula is a single identifier. */
+
+            pscopy(&lcl_str, tie, t);
+            entry = entrynb(dico, ds_get_buf(&lcl_str));
+            ds_free(&lcl_str);
+            if (entry && (entry->tp == NUPA_STRING)) {
+                if (qstr_p)
+                    pscat(qstr_p, entry->sbbase, NULL);
+                ok = TRUE;
+            } else {
+                return NULL;
+            }
+        }
+        if (*t == '}')
+            ++t;
+    }
+    return ok ? (char *)t : NULL;
+}
+
 /* stupid, produce a string representation of a given double
  *   to be spliced back into the circuit deck
  * we want *exactly* 25 chars, we have
@@ -1113,7 +1186,8 @@ evaluate_expr(dico_t *dico, DSTRINGPTR qstr_p, const char *t, const char * const
     double u;
 
     ds_clear(qstr_p);
-
+    if (string_expr(dico, qstr_p, t, t_end))
+        return 0;
     u = formula(dico, t, t_end, &err);
     if (err)
         return err;
@@ -1247,38 +1321,31 @@ getword(const char *s, DSTRINGPTR tstr_p)
 
 
 static char *
-getexpress(nupa_type *type, DSTRINGPTR tstr_p, const char *s)
+getexpress(dico_t *dico, nupa_type *type, DSTRINGPTR tstr_p, const char *s)
 /* returns expression-like string until next separator
    Input  i=position before expr, output  i=just after expr, on separator.
    returns tpe=='R' if (numeric, 'S' if (string only
 */
 {
-    const char * const s_end = s + strlen(s);
+    const char *s_end = s + strlen(s);
     const char *p;
     nupa_type tpe;
 
     while ((s < s_end - 1) && ((unsigned char)(* s) <= ' '))
         s++;                    /*white space ? */
 
-    if (*s == '"') {            /* string constant */
-
-        s++;
-        p = s;
-
-        while ((p < s_end - 1) && (*p != '"'))
-            p++;
-
-        do
-            p++;
-        while ((p < s_end) && ((unsigned char)(*p) <= ' '));
+    /* Check for injected semicolon separator in assignment list. */
+    p = strchr(s, ';');
+    if (p)
+        s_end = p;
 
+    p = string_expr(dico, NULL, s, s_end);
+    if (p) {
         tpe = NUPA_STRING;
-
     } else {
 
         if (*s == '{')
             s++;
-
         p = s;
 
         for (; p < s_end; p++) {
@@ -1304,7 +1371,6 @@ getexpress(nupa_type *type, DSTRINGPTR tstr_p, const char *s)
                 }
             }
         }
-
         tpe = NUPA_REAL;
     }
 
@@ -1313,9 +1379,6 @@ getexpress(nupa_type *type, DSTRINGPTR tstr_p, const char *s)
     if (*p == '}')
         p++;
 
-    if (tpe == NUPA_STRING)
-        p++;                    /* beyond quote */
-
     if (type)
         *type = tpe;
 
@@ -1334,7 +1397,8 @@ nupa_assignment(dico_t *dico, const char *s, char mode)
     /* s has the format: ident = expression; ident= expression ...  */
     const char * const s_end = s + strlen(s);
     const char *p = s;
-
+    const char *tmp;
+    char       *sval = NULL;
     bool error = 0;
     nupa_type dtype;
     int wval = 0;
@@ -1369,23 +1433,26 @@ nupa_assignment(dico_t *dico, const char *s, char mode)
             break;
         }
 
-        p = getexpress(&dtype, &ustr, p + 1) + 1;
+        p = getexpress(dico, &dtype, &ustr, p + 1) + 1;
 
+        tmp = ds_get_buf(&ustr);
         if (dtype == NUPA_REAL) {
-            const char *tmp = ds_get_buf(&ustr);
             rval = formula(dico, tmp, tmp + strlen(tmp), &error);
             if (error) {
                 message(dico,
                         " Formula() error.\n"
-                        "      %s\n", s);
+                        "      |%s| : |%s|=|%s|\n", s, ds_get_buf(&tstr), ds_get_buf(&ustr));
                 break;
             }
         } else if (dtype == NUPA_STRING) {
-            wval = (int) (p - s);
+            DS_CREATE(sstr, 200);
+            string_expr(dico, &sstr, tmp, tmp + strlen(tmp));
+            sval = copy(ds_get_buf(&sstr));
+            ds_free(&sstr);
         }
 
         error = nupa_define(dico, ds_get_buf(&tstr), mode /* was ' ' */ ,
-                            dtype, rval, wval, NULL);
+                            dtype, rval, wval, sval);
         if (error)
             break;
 
@@ -1445,9 +1512,10 @@ nupa_subcktcall(dico_t *dico, const char *s, const char *x,
 
     /***** first, analyze the subckt definition line */
     n = 0; /* number of parameters if any */
-
     scopys(&tstr, s);
 
+    /* Get the subcircuit name in subname. */
+
     const char *j2 = strstr(ds_get_buf(&tstr), "subckt");
     if (j2) {
         j2 = skip_ws(j2 + 6);     /* skip subckt and whitespace */
@@ -1456,6 +1524,8 @@ nupa_subcktcall(dico_t *dico, const char *s, const char *x,
         err = message(dico, " ! a subckt line!\n");
     }
 
+    /* Scan the .subckt line for assignments, copying templates to idlist. */
+
     const char *i2 = strstr(ds_get_buf(&tstr), "params:");
 
     if (i2) {
@@ -1510,7 +1580,7 @@ nupa_subcktcall(dico_t *dico, const char *s, const char *x,
         char * const t_p = ds_get_buf(&tstr);
         char *jp = NULL;
 
-        /* search for the last occurence of `subname' in the given line */
+        /* Search for the last occurence of `subname' in the call line. */
         for (;;) {
             char *next_p = search_isolated_identifier(jp ? jp + 1 : t_p,
                     ds_get_buf(&subname));
@@ -1528,7 +1598,6 @@ nupa_subcktcall(dico_t *dico, const char *s, const char *x,
             /* jp is pointing to the 1st position of arglist now */
 
             while (*jp) {
-
                 /* try to fetch valid arguments */
                 char *kp = jp;
                 ds_clear(&ustr);
@@ -1538,13 +1607,16 @@ nupa_subcktcall(dico_t *dico, const char *s, const char *x,
                     jp = skip_non_ws(kp);
                     pscopy(&ustr, kp, jp);
                 } else if (*kp == '{') {
-                    jp = getexpress(NULL, &ustr, jp);
+                    jp = getexpress(dico, NULL, &ustr, jp);
                 } else {
                     jp++;
                     if ((unsigned char) (*kp) > ' ')
                         message(dico, "Subckt call, symbol %c not understood\n", *kp);
                 }
 
+                /* Substitute the parameter for one of the '$' characters
+                 * in idlist.
+                 */
                 char * const u_p = ds_get_buf(&ustr);
                 if (*u_p) {
                     char * const idlist_p = ds_get_buf(&idlist);