diff --git a/.gitignore b/.gitignore
index 1e60eda0..f0e2480e 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,3 +1,4 @@
 bin
 build
 *~
+.vs
diff --git a/thecl/ecsparse.y b/thecl/ecsparse.y
index 3a1cad67..1807e1a4 100644
--- a/thecl/ecsparse.y
+++ b/thecl/ecsparse.y
@@ -1199,7 +1199,7 @@ instr_set_types(
 
         if (new_type != param->type &&
             !(param->type == 'z' && (new_type == 'm' || new_type == 'x')) &&
-            !(param->type == 'S' && new_type == 's')) {
+            !(param->type == 'S' && (new_type == 's' || new_type == 'U'))) {
 
             char errbuf[256];
             snprintf(errbuf, 256, "instr_set_types: in sub %s: wrong argument "
diff --git a/thecl/thecl10.c b/thecl/thecl10.c
index e057d6c9..75c663af 100644
--- a/thecl/thecl10.c
+++ b/thecl/thecl10.c
@@ -527,7 +527,7 @@ static const id_format_pair_t th12_fmts[] = {
     { 424, "S" },
     { 425, "" },
     { 426, "f" },
-    { 427, "SfC" },
+    { 427, "SfU" },
     { 428, "SSSx" },
     { 429, "ffff" },
     { 430, "ffffff" },
@@ -583,7 +583,7 @@ static const id_format_pair_t th12_fmts[] = {
     { 523, "Sff" },
     { 524, "Sf" },
     { 525, "Sff" },
-    { 526, "fC" },
+    { 526, "fU" },
     { 527, "" },
     { 528, "" },
     { 529, "S" },
diff --git a/util/value.c b/util/value.c
index e7e67c56..7ac6debd 100644
--- a/util/value.c
+++ b/util/value.c
@@ -80,7 +80,7 @@ value_from_data(
     case 'S':
         READ(S, sizeof(int32_t));
     case 'C':
-        READ(C, sizeof(int32_t));
+        READ(C, sizeof(uint32_t));
         break;
     case 'z':
         value->val.z = malloc(data_length);
@@ -196,6 +196,13 @@ value_from_text(
     case 'S':
         READ(d, value->val.S);
         break;
+    case 'C':
+        if (sscanf(text, "#%02hhx%02hhx%02hhx%02hhx", &value->val.C[0], &value->val.C[1], &value->val.C[2], &value->val.C[3]) != 4) {
+                fprintf(stderr, "%s:value_from_text: couldn't parse '%c' from  \"%s\"\n", argv0, value->type, text);
+                return 0;
+        }
+        READ(u, value->val.C);
+        break;
     case 'z':
         value->val.z = strdup(text);
         break;
@@ -299,6 +306,8 @@ value_to_data(
         WRITE(U, sizeof(uint32_t));
     case 'S':
         WRITE(S, sizeof(int32_t));
+    case 'C':
+        WRITE(C, sizeof(uint32_t));
     case 'z': {
         size_t zlen = strlen(value->val.z);
         if (data_length < zlen) {
@@ -344,6 +353,8 @@ value_size(
         return sizeof(uint32_t);
     case 'S':
         return sizeof(int32_t);
+    case 'C':
+        return sizeof(uint32_t);
     case 'z':
         return strlen(value->val.z);
     case 'm':