diff --git a/compiler/AST/build.cpp b/compiler/AST/build.cpp
index 69e646d1990d..189f94bfe897 100644
--- a/compiler/AST/build.cpp
+++ b/compiler/AST/build.cpp
@@ -1993,6 +1993,8 @@ buildClassDefExpr(const char* name,
   // possible in the compiler. gatherWellKnownTypes runs too late to be of use
   // to us.
   if (strcmp("string", name) == 0) {
+    // If we want to change dtString to refer to string(ascii),
+    // this might be the place to do it.
     *dtString = *ct;
     // These fields get overwritten with `ct` by the assignment. These fields are
     // set to `this` by the AggregateType constructor so they should still be
diff --git a/compiler/AST/symbol.cpp b/compiler/AST/symbol.cpp
index ace51bc06971..83f8c412d036 100644
--- a/compiler/AST/symbol.cpp
+++ b/compiler/AST/symbol.cpp
@@ -561,6 +561,9 @@ GenRet VarSymbol::codegen() {
   if( outfile ) {
     // dtString immediates don't actually codegen as immediates, we just use
     // them for param string functionality.
+
+    // Consider changing this isStringType to support
+    // utf-8 and ascii string literals
     if (immediate && ret.chplType != dtString) {
       ret.isLVPtr = GEN_VAL;
       if (immediate->const_kind == CONST_KIND_STRING) {
@@ -3160,6 +3163,9 @@ VarSymbol *new_StringSymbol(const char *str) {
       gFalse);                    // owned = false
   ctor->insertAtTail(gFalse);     // needToCopy = false
 
+  // Either:
+    // change dtString to be concrete, or
+    // make this new VarSymbol have a concrete string(ascii) type
   s = new VarSymbol(astr("_str_literal_", istr(literal_id++)), dtString);
   s->addFlag(FLAG_NO_AUTO_DESTROY);
   s->addFlag(FLAG_CONST);
@@ -3386,6 +3392,8 @@ static Type*
 immediate_type(Immediate *imm) {
   switch (imm->const_kind) {
     case CONST_KIND_STRING: {
+      // We might need to have string_kind for UTF-8 and ASCII strings.
+      // (would need to change ifa/num.h and ifa/num.cpp)
       if (imm->string_kind == STRING_KIND_STRING) {
         return dtString;
       } else if (imm->string_kind == STRING_KIND_C_STRING) {
diff --git a/compiler/AST/type.cpp b/compiler/AST/type.cpp
index c050ea89ba25..97559f1e7b08 100644
--- a/compiler/AST/type.cpp
+++ b/compiler/AST/type.cpp
@@ -1970,6 +1970,9 @@ bool isArrayClass(Type* type) {
 bool isString(Type* type) {
   bool retval = false;
 
+  // Pretty sure this needs to return true if isStringType
+  // would return true
+
   if (AggregateType* aggr = toAggregateType(type))
     retval = strcmp(aggr->symbol->name, "string") == 0;
 
diff --git a/compiler/include/type.h b/compiler/include/type.h
index 5c63d2748029..c3088067f967 100644
--- a/compiler/include/type.h
+++ b/compiler/include/type.h
@@ -244,7 +244,12 @@ TYPE_EXTERN PrimitiveType* dtSyncVarAuxFields;
 TYPE_EXTERN PrimitiveType* dtSingleVarAuxFields;
 
 // Well-known types
-TYPE_EXTERN AggregateType* dtString;
+TYPE_EXTERN AggregateType* dtString; // consider renaming this dtStringGeneric
+
+// Add:
+// dtStringAscii
+// dtStringUTF8
+
 TYPE_EXTERN AggregateType* dtArray;
 TYPE_EXTERN AggregateType* dtBaseArr;
 TYPE_EXTERN AggregateType* dtBaseDom;
@@ -296,12 +301,16 @@ bool isDistImplType(Type* t);
 bool isSyncType(Type* t);
 bool isAtomicType(Type* t);
 bool isRefIterType(Type* t);
+// isStringType
+// returns true for generic version, string(ascii), string(utf-8)
+// ie all instantiations of the generic version
 
 bool isSubClass(Type* type, Type* baseType);
 bool isDistClass(Type* type);
 bool isDomainClass(Type* type);
 bool isArrayClass(Type* type);
 
+// ? is same as isStringType?
 bool isString(Type* type);
 bool isUserDefinedRecord(Type* type);
 
diff --git a/compiler/optimizations/bulkCopyRecords.cpp b/compiler/optimizations/bulkCopyRecords.cpp
index 2cc63cdbc83f..72a6438bd802 100644
--- a/compiler/optimizations/bulkCopyRecords.cpp
+++ b/compiler/optimizations/bulkCopyRecords.cpp
@@ -66,6 +66,8 @@ static bool isTrivialAssignment(FnSymbol* fn)
   // Skip this optimization for string/wide string types
   // (due to problems providing additional arguments for
   //  PRIM_ASSIGN).
+
+  // This needs to call isStringType or check for either UTF-8/ascii string
   if (argType == dtString)
     return false;
 
diff --git a/compiler/passes/buildDefaultFunctions.cpp b/compiler/passes/buildDefaultFunctions.cpp
index a90bb2a07802..82e05b6c8ee4 100644
--- a/compiler/passes/buildDefaultFunctions.cpp
+++ b/compiler/passes/buildDefaultFunctions.cpp
@@ -754,6 +754,7 @@ static void build_enum_cast_function(EnumType* et) {
   fn->addFlag(FLAG_COMPILER_GENERATED);
   arg1 = new ArgSymbol(INTENT_BLANK, "t", dtAny);
   arg1->addFlag(FLAG_TYPE_VARIABLE);
+  // This argument should be a generic string type
   arg2 = new ArgSymbol(INTENT_BLANK, "_arg2", dtString);
   fn->insertFormalAtTail(arg1);
   fn->insertFormalAtTail(arg2);
@@ -1300,6 +1301,7 @@ static void buildDefaultReadWriteFunctions(AggregateType* ct) {
 
 
 static void buildStringCastFunction(EnumType* et) {
+  // Think this one should be the generic string
   if (function_exists("_cast", 2, dtString, et))
     return;
 
@@ -1311,6 +1313,8 @@ static void buildStringCastFunction(EnumType* et) {
   ArgSymbol* arg = new ArgSymbol(INTENT_BLANK, "this", et);
   arg->addFlag(FLAG_ARG_THIS);
   fn->insertFormalAtTail(arg);
+  // This one needs to turn into : string
+  // with the generic string type
   fn->where = new BlockStmt(new CallExpr("==", t, dtString->symbol));
 
   for_enums(constant, et) {
diff --git a/compiler/passes/checkResolved.cpp b/compiler/passes/checkResolved.cpp
index 518ae6d43280..943e06cb1f82 100644
--- a/compiler/passes/checkResolved.cpp
+++ b/compiler/passes/checkResolved.cpp
@@ -276,6 +276,7 @@ static void checkExternProcs() {
       continue;
 
     for_formals(formal, fn) {
+      // This should call isStringType
       if (formal->typeInfo() == dtString) {
         if (fn->instantiatedFrom == NULL) {
           USR_FATAL_CONT(fn, "extern procedures should not take arguments of "
diff --git a/compiler/passes/filesToAST.cpp b/compiler/passes/filesToAST.cpp
index 4ae62d5808df..0dc6d1b448d1 100644
--- a/compiler/passes/filesToAST.cpp
+++ b/compiler/passes/filesToAST.cpp
@@ -57,6 +57,8 @@ static WellKnownType sWellKnownTypes[] = {
   {"BaseDom",            &dtBaseDom,       true},
   {"BaseDist",           &dtDist,          true},
   {"chpl_main_argument", &dtMainArgument, false}
+  // Can dtStringAscii be added here to
+  // refer to a type asciiString = string(ascii) ?
 };
 
 
diff --git a/compiler/passes/parallel.cpp b/compiler/passes/parallel.cpp
index 32370c4de58e..30838c8c12df 100644
--- a/compiler/passes/parallel.cpp
+++ b/compiler/passes/parallel.cpp
@@ -877,6 +877,7 @@ static void findHeapVarsAndRefs(Map<Symbol*,Vec<SymExpr*>*>& defMap,
             !isSyncType(def->sym->type) &&
             // Dont try to broadcast string literals, they'll get fixed in
             // another manner
+            // Should call isStringType
             (def->sym->type != dtString)))) {
         // replicate global const of primitive type
         INT_ASSERT(defMap.get(def->sym) && defMap.get(def->sym)->n == 1);
diff --git a/compiler/resolution/functionResolution.cpp b/compiler/resolution/functionResolution.cpp
index 0fc39ac72445..162addbb1a1a 100644
--- a/compiler/resolution/functionResolution.cpp
+++ b/compiler/resolution/functionResolution.cpp
@@ -1027,6 +1027,7 @@ resolveFormals(FnSymbol* fn) {
         continue;
 
       // Don't pass dtString params in by reference
+      // Should call isStringType
       if(formal->type == dtString && formal->hasFlag(FLAG_INSTANTIATED_PARAM))
         continue;
 
@@ -1242,6 +1243,7 @@ canInstantiate(Type* actualType, Type* formalType) {
       (is_int_type(actualType) || is_uint_type(actualType) || is_imag_type(actualType) ||
        is_real_type(actualType) || is_complex_type(actualType)))
     return true;
+  // use isStringType, including possibly a generic string
   if (formalType == dtString && actualType==dtStringC)
     return true;
   if (formalType == dtStringC && actualType==dtStringCopy)
@@ -1325,6 +1327,8 @@ static bool canParamCoerce(Type* actualType, Symbol* actualSym, Type* formalType
         if (fits_in_uint(get_width(formalType), var->immediate))
           return true;
   }
+
+  // isStringType(actualType)
   if (formalType == dtStringC && actualType == dtString)
     if (actualSym && actualSym->isImmediate())
       return true;
@@ -1370,6 +1374,8 @@ canCoerce(Type* actualType, Symbol* actualSym, Type* formalType, FnSymbol* fn, b
   }
   if (actualType->symbol->hasFlag(FLAG_REF))
     return canDispatch(actualType->getValType(), NULL, formalType, fn, promotes);
+
+  // isStringType(formalType)
   if (formalType == dtString && actualType == dtStringCopy)
     return true;
   if (formalType == dtStringC && actualType == dtStringCopy)
@@ -1599,7 +1605,9 @@ computeGenericSubs(SymbolMap &subs,
           //   foo("bar");
           // and pass "bar" as a c_string instead of a string
           if (fn->hasFlag(FLAG_EXTERN) && (formal->type == dtAny) &&
+              // (type == dtString) -> isStringType(type)
               (!formal->hasFlag(FLAG_PARAM)) && (type == dtString) &&
+              //  isStringType(alignedA...)
               (alignedActuals.v[i]->type == dtString) &&
               (alignedActuals.v[i]->isImmediate())) {
             subs.put(formal, dtStringC->symbol);
@@ -2214,6 +2222,8 @@ static bool paramWorks(Symbol* actual, Type* formalType) {
       return fits_in_uint(get_width(formalType), imm);
     }
     if (imm->const_kind == CONST_KIND_STRING) {
+      // isStringType for now, but maybe put a comment
+      // that it it wouldn't work for UTF-16 e.g.
       if (formalType == dtStringC && actual->type == dtString) {
         return true;
       }
@@ -5658,6 +5668,10 @@ preFold(Expr* expr) {
                      is_bool_type(oldType)) &&
                     (is_int_type(newType) || is_uint_type(newType) ||
                      is_bool_type(newType) || is_enum_type(newType) ||
+                     // newType can be string(ascii) or string(utf8)
+                     // couldn't be called with generic
+                     // isStringType and maybe a comment about
+                     // UTF-16 being disqualified
                      newType == dtString || newType == dtStringC)) {
                   VarSymbol* typevar = toVarSymbol(newType->defaultValue);
                   EnumType* typeenum = toEnumType(newType);
@@ -5669,9 +5683,12 @@ preFold(Expr* expr) {
                     coerce_immediate(var->immediate, &coerce);
                     result = new SymExpr(new_ImmediateSymbol(&coerce));
                     call->replace(result);
+                  // isStringType
                   } else if (newType == dtString) {
                     // typevar will be null for dtString so we need a special
                     // case.
+                    
+                    // newType -> STRING_KIND_STRING_UTF8/ASCII
                     Immediate coerce = Immediate("", STRING_KIND_STRING);
                     coerce_immediate(var->immediate, &coerce);
                     result = new SymExpr(new_StringSymbol(coerce.v_string));
@@ -5699,6 +5716,7 @@ preFold(Expr* expr) {
                   } else {
                     INT_FATAL("unexpected case in cast_fold");
                   }
+                // isStringType but not UTF-16
                 } else if (oldType == dtString && newType == dtStringC) {
                   result = new SymExpr(new_CStringSymbol(var->immediate->v_string));
                   call->replace(result);
@@ -5708,6 +5726,7 @@ preFold(Expr* expr) {
           } else if (EnumSymbol* enumSym = toEnumSymbol(sym->var)) {
             if (SymExpr* sym = toSymExpr(call->get(1))) {
               Type* newType = sym->var->type;
+              // isStringType
               if (newType == dtString) {
                 result = new SymExpr(new_StringSymbol(enumSym->name));
                 call->replace(result);
@@ -6583,6 +6602,8 @@ postFold(Expr* expr) {
       if (lhs->var->isParameter() && rhs->var->isParameter()) {
         const char* lstr = get_string(lhs);
         const char* rstr = get_string(rhs);
+        // isStringType
+        // alternatively, could be !(dtStringC || dtStringCopy)
         if (lhs->var->type == dtString)
           result = new SymExpr(new_StringSymbol(astr(lstr, rstr)));
         else
@@ -6935,6 +6956,8 @@ resolveExpr(Expr* expr) {
         // Don't try to resolve the defaultTypeConstructor for string literals
         // (resolution ordering issue, string literals are encountered too early
         // on and we don't know enough to be able to resolve them at that point)
+
+        // isStringType, but won't be generic
         if (!(ct == dtString && (sym->var->isParameter() ||
                                  sym->var->hasFlag(FLAG_INSTANTIATED_PARAM))) &&
             !ct->symbol->hasFlag(FLAG_GENERIC) &&
@@ -7823,6 +7846,37 @@ resolve() {
 
   resolveExternVarSymbols();
 
+  // At least by here
+  // resolve string(ascii) and string(utf8) types
+  // set dtStringAscii and dtStringUTF8 to them
+
+
+  // 2 approaches:
+  // 1) resolve string(ascii) and string(utf8)
+  //    by creating calls to their type constructor
+
+  /* 
+      // ? is the type constructor really called string, or something else?
+     
+      CallExpr* asciiEnum = new CallExpr("chpl_get_string_ascii_enum");
+
+
+      CallExpr* call = new CallExpr(dtString->defaultTypeConstructor
+                                    asciiEnum);
+
+      // insert it in the AST somewhere...
+      // Try putting it into the String module's init function?
+      resolveCallAndCallee(call);
+   */
+
+  // 2) in String.chpl, make declarations like
+  //     type asciiString = string(ascii);
+  //     type utf8String = string(utf8);
+
+  // at this point, you'd have say
+  //   make new SymExpr( "string_ascii" )
+  //   dtStringAscii = resolveTypeAlias(se)
+
   // --ipe does not build a mainModule
   if (mainModule)
     resolveUses(mainModule);
diff --git a/compiler/resolution/generics.cpp b/compiler/resolution/generics.cpp
index 728aee10dc33..7470846d62fd 100644
--- a/compiler/resolution/generics.cpp
+++ b/compiler/resolution/generics.cpp
@@ -466,6 +466,7 @@ renameInstantiatedType(TypeSymbol* sym, SymbolMap& subs, FnSymbol* fn) {
         VarSymbol* var = toVarSymbol(value);
         if (var && var->immediate) {
           Immediate* immediate = var->immediate;
+          // should use isStringType
           if (var->type == dtString || var->type == dtStringC)
             renameInstantiatedTypeString(sym, var);
           else if (immediate->const_kind == NUM_KIND_BOOL) {
diff --git a/compiler/resolution/wrappers.cpp b/compiler/resolution/wrappers.cpp
index 26d74268c105..08063fa3f608 100644
--- a/compiler/resolution/wrappers.cpp
+++ b/compiler/resolution/wrappers.cpp
@@ -668,6 +668,7 @@ void coerceActuals(FnSymbol* fn, CallInfo* info) {
       c2 = false;
       Type* actualType = actualSym->type;
       if (needToAddCoercion(actualType, actualSym, formalType, fn)) {
+        // actualType == dtString -> isStringType(actualType)
         if (formalType == dtStringC && actualType == dtString && actualSym->isImmediate()) {
           // We do this swap since we know the string is a valid literal
           // There also is no cast defined for string->c_string on purpose (you
diff --git a/modules/internal/String.chpl b/modules/internal/String.chpl
index 60a2bce80f05..d6089847e0cb 100644
--- a/modules/internal/String.chpl
+++ b/modules/internal/String.chpl
@@ -1249,6 +1249,12 @@ module String {
 
   } // end record string
 
+  // Part of one approach ?
+  // proc chpl_get_string_ascii_enum() {
+  //   return Encoding.ascii;
+  // }
+  // type string_ascii = string(Encoding.ascii);
+  // type string_utf8 = string(Encoding.utf8);
 
   // We'd like this to be by ref, but doing so leads to an internal
   // compiler error.  See