diff --git a/grammars/README.md b/grammars/README.md
index a63198b5aeb8e..adf089af643b6 100644
--- a/grammars/README.md
+++ b/grammars/README.md
@@ -36,7 +36,7 @@ castle ::= ...
 
 ## Non-Terminals and Terminals
 
-Non-terminal symbols (rule names) stand for a pattern of terminals and other non-terminals. They are required to be a dashed lowercase word, like `move`, `castle`, or `check-mate`.
+Non-terminal symbols (rule names) stand for a pattern of terminals and other non-terminals. Rule names can be composed of letters (both uppercase and lowercase), numbers, dashes, and underscores. For example: `move`, `castle`, `check-mate`, `dataType`, `UPPER-CASE`, or `rule_123` are all valid non-terminal names.
 
 Terminals are actual characters ([code points](https://en.wikipedia.org/wiki/Code_point)). They can be specified as a sequence like `"1"` or `"O-O"` or as ranges like `[1-9]` or `[NBKQR]`.
 
diff --git a/src/llama-impl.cpp b/src/llama-impl.cpp
index 6ec709dd323a6..e5bd07604d643 100644
--- a/src/llama-impl.cpp
+++ b/src/llama-impl.cpp
@@ -122,8 +122,18 @@ static std::string gguf_data_to_str(enum gguf_type type, const void * data, int
         case GGUF_TYPE_INT32:   return std::to_string(((const int32_t  *)data)[i]);
         case GGUF_TYPE_UINT64:  return std::to_string(((const uint64_t *)data)[i]);
         case GGUF_TYPE_INT64:   return std::to_string(((const int64_t  *)data)[i]);
-        case GGUF_TYPE_FLOAT32: return std::to_string(((const float    *)data)[i]);
-        case GGUF_TYPE_FLOAT64: return std::to_string(((const double   *)data)[i]);
+        case GGUF_TYPE_FLOAT32: {
+            std::ostringstream oss;
+            oss.imbue(std::locale::classic());
+            oss << ((const float *)data)[i];
+            return oss.str();
+        }
+        case GGUF_TYPE_FLOAT64: {
+            std::ostringstream oss;
+            oss.imbue(std::locale::classic());
+            oss << ((const double *)data)[i];
+            return oss.str();
+        }
         case GGUF_TYPE_BOOL:    return ((const bool *)data)[i] ? "true" : "false";
         default:                return format("unknown type %d", type);
     }