diff --git a/doc/ca65.sgml b/doc/ca65.sgml
index b68acb639..37349f409 100644
--- a/doc/ca65.sgml
+++ b/doc/ca65.sgml
@@ -2758,15 +2758,19 @@ See: <tt><ref id=".ASCIIZ" name=".ASCIIZ"></tt>,<tt><ref id=".CHARMAP" name=".CH
   This directive may be used to enable one or more compatibility features
   of the assembler. While the use of <tt/.FEATURE/ should be avoided when
   possible, it may be useful when porting sources written for other
-  assemblers. There is no way to switch a feature off, once you have
-  enabled it, so using
+  assemblers. After the feature name an optional '+' or '-' may specify whether
+  to enable or disable the feature (enable if omitted). Multiple features may be
+  enabled, separated by commas. Examples:
 
   <tscreen><verb>
-        .FEATURE        xxx
+        ; enable c_comments
+        .feature   c_comments
+        .feature   c_comments +
+        ; enable force_range, disable underline_in_numbers, enable labels_without_colons
+        .feature   force_range, underline_in_numbers -, labels_without_colons +
+        .feature   force_range +, underline_in_numbers off, labels_without_colons on
   </verb></tscreen>
 
-  will enable the feature until end of assembly is reached.
-
   The following features are available:
 
   <descrip>
diff --git a/src/ca65/feature.c b/src/ca65/feature.c
index 754b645cf..41177d66b 100644
--- a/src/ca65/feature.c
+++ b/src/ca65/feature.c
@@ -98,38 +98,30 @@ feature_t FindFeature (const StrBuf* Key)
 
 
 
-feature_t SetFeature (const StrBuf* Key)
-/* Find the feature and set the corresponding flag if the feature is known.
-** In any case, return the feature found. An invalid Key will return
-** FEAT_UNKNOWN.
+void SetFeature (feature_t Feature, unsigned char On)
+/* Set the corresponding feature flag if Feature is valid.
 */
 {
-    /* Map the string to an enum value */
-    feature_t Feature = FindFeature (Key);
-
     /* Set the flags */
     switch (Feature) {
-        case FEAT_DOLLAR_IS_PC:               DollarIsPC        = 1;    break;
-        case FEAT_LABELS_WITHOUT_COLONS:      NoColonLabels     = 1;    break;
-        case FEAT_LOOSE_STRING_TERM:          LooseStringTerm   = 1;    break;
-        case FEAT_LOOSE_CHAR_TERM:            LooseCharTerm     = 1;    break;
-        case FEAT_AT_IN_IDENTIFIERS:          AtInIdents        = 1;    break;
-        case FEAT_DOLLAR_IN_IDENTIFIERS:      DollarInIdents    = 1;    break;
-        case FEAT_LEADING_DOT_IN_IDENTIFIERS: LeadingDotInIdents= 1;    break;
-        case FEAT_ORG_PER_SEG:                OrgPerSeg         = 1;    break;
-        case FEAT_PC_ASSIGNMENT:              PCAssignment      = 1;    break;
-        case FEAT_MISSING_CHAR_TERM:          MissingCharTerm   = 1;    break;
-        case FEAT_UBIQUITOUS_IDENTS:          UbiquitousIdents  = 1;    break;
-        case FEAT_C_COMMENTS:                 CComments         = 1;    break;
-        case FEAT_FORCE_RANGE:                ForceRange        = 1;    break;
-        case FEAT_UNDERLINE_IN_NUMBERS:       UnderlineInNumbers= 1;    break;
-        case FEAT_ADDRSIZE:                   AddrSize          = 1;    break;
-        case FEAT_BRACKET_AS_INDIRECT:        BracketAsIndirect = 1;    break;
-        case FEAT_STRING_ESCAPES:             StringEscapes     = 1;    break;
-        case FEAT_LONG_JSR_JMP_RTS:           LongJsrJmpRts     = 1;    break;
-        default:                         /* Keep gcc silent */          break;
+        case FEAT_DOLLAR_IS_PC:               DollarIsPC        = On;    break;
+        case FEAT_LABELS_WITHOUT_COLONS:      NoColonLabels     = On;    break;
+        case FEAT_LOOSE_STRING_TERM:          LooseStringTerm   = On;    break;
+        case FEAT_LOOSE_CHAR_TERM:            LooseCharTerm     = On;    break;
+        case FEAT_AT_IN_IDENTIFIERS:          AtInIdents        = On;    break;
+        case FEAT_DOLLAR_IN_IDENTIFIERS:      DollarInIdents    = On;    break;
+        case FEAT_LEADING_DOT_IN_IDENTIFIERS: LeadingDotInIdents= On;    break;
+        case FEAT_ORG_PER_SEG:                OrgPerSeg         = On;    break;
+        case FEAT_PC_ASSIGNMENT:              PCAssignment      = On;    break;
+        case FEAT_MISSING_CHAR_TERM:          MissingCharTerm   = On;    break;
+        case FEAT_UBIQUITOUS_IDENTS:          UbiquitousIdents  = On;    break;
+        case FEAT_C_COMMENTS:                 CComments         = On;    break;
+        case FEAT_FORCE_RANGE:                ForceRange        = On;    break;
+        case FEAT_UNDERLINE_IN_NUMBERS:       UnderlineInNumbers= On;    break;
+        case FEAT_ADDRSIZE:                   AddrSize          = On;    break;
+        case FEAT_BRACKET_AS_INDIRECT:        BracketAsIndirect = On;    break;
+        case FEAT_STRING_ESCAPES:             StringEscapes     = On;    break;
+        case FEAT_LONG_JSR_JMP_RTS:           LongJsrJmpRts     = On;    break;
+        default:                                                         break;
     }
-
-    /* Return the value found */
-    return Feature;
 }
diff --git a/src/ca65/feature.h b/src/ca65/feature.h
index a29ee0172..8eeb62e6f 100644
--- a/src/ca65/feature.h
+++ b/src/ca65/feature.h
@@ -87,10 +87,8 @@ feature_t FindFeature (const StrBuf* Key);
 ** feature is invalid, return FEAT_UNKNOWN.
 */
 
-feature_t SetFeature (const StrBuf* Key);
-/* Find the feature and set the corresponding flag if the feature is known.
-** In any case, return the feature found. An invalid Key will return
-** FEAT_UNKNOWN.
+void SetFeature (feature_t Feature, unsigned char On);
+/* Set the corresponding feature flag if Feature is valid.
 */
 
 
diff --git a/src/ca65/main.c b/src/ca65/main.c
index 9710924bf..7183ff046 100644
--- a/src/ca65/main.c
+++ b/src/ca65/main.c
@@ -489,12 +489,15 @@ static void OptDebugInfo (const char* Opt attribute ((unused)),
 static void OptFeature (const char* Opt attribute ((unused)), const char* Arg)
 /* Set an emulation feature */
 {
-    /* Make a string buffer from Arg */
-    StrBuf Feature;
+    /* Make a string buffer from Arg and use it to find the feature. */
+    StrBuf StrFeature;
+    feature_t Feature = FindFeature (SB_InitFromString (&StrFeature, Arg));
 
-    /* Set the feature, check for errors */
-    if (SetFeature (SB_InitFromString (&Feature, Arg)) == FEAT_UNKNOWN) {
+    /* Enable the feature, check for errors */
+    if (Feature == FEAT_UNKNOWN) {
         AbEnd ("Illegal emulation feature: '%s'", Arg);
+    } else {
+        SetFeature (Feature, 1);
     }
 }
 
diff --git a/src/ca65/pseudo.c b/src/ca65/pseudo.c
index 843f5b9d2..1877512d5 100644
--- a/src/ca65/pseudo.c
+++ b/src/ca65/pseudo.c
@@ -1023,7 +1023,10 @@ static void DoFatal (void)
 static void DoFeature (void)
 /* Switch the Feature option */
 {
-    /* Allow a list of comma separated keywords */
+    feature_t Feature;
+    unsigned char On;
+
+    /* Allow a list of comma separated feature keywords with optional +/- or ON/OFF */
     while (1) {
 
         /* We expect an identifier */
@@ -1034,18 +1037,24 @@ static void DoFeature (void)
 
         /* Make the string attribute lower case */
         LocaseSVal ();
-
-        /* Set the feature and check for errors */
-        if (SetFeature (&CurTok.SVal) == FEAT_UNKNOWN) {
+        Feature = FindFeature(&CurTok.SVal);
+        if (Feature == FEAT_UNKNOWN) {
             /* Not found */
             ErrorSkip ("Invalid feature: '%m%p'", &CurTok.SVal);
             return;
-        } else {
-            /* Skip the keyword */
-            NextTok ();
+        }
+        NextTok ();
+
+        /* Optional +/- or ON/OFF */
+        On = 1;
+        if (CurTok.Tok != TOK_COMMA && !TokIsSep (CurTok.Tok)) {
+            SetBoolOption(&On);
         }
 
-        /* Allow more than one keyword */
+        /* Apply feature setting. */
+        SetFeature (Feature, On);
+
+        /* Allow more than one feature separated by commas. */
         if (CurTok.Tok == TOK_COMMA) {
             NextTok ();
         } else {
diff --git a/test/asm/listing/108-long-rts.s b/test/asm/listing/108-long-rts.s
new file mode 100644
index 000000000..a8bf860cd
--- /dev/null
+++ b/test/asm/listing/108-long-rts.s
@@ -0,0 +1,8 @@
+; test of long-rts promotion
+
+.p816
+.feature long_jsr_jmp_rts
+.smart +
+.proc farproc : far
+    rts ; should be $6B (RTL) and not $60 (RTS)
+.endproc
diff --git a/test/asm/listing/readme.txt b/test/asm/listing/readme.txt
index e43f2008a..d6280b954 100644
--- a/test/asm/listing/readme.txt
+++ b/test/asm/listing/readme.txt
@@ -6,22 +6,38 @@ The name of a test is everything in the form <test>.s.
 
 The following reference files can be added:
 
-- <test>.bin-ref:
+- ref/<test>.bin-ref:
   This is a reference for the resulting binary.
   The binary as binary tested against this file.
   If they are not equal, the test fails.
 
-- <test>.list-ref
+- ref/<test>.list-ref
   This is a reference for the resulting listing output
   This file *must* have the first line of the listing removed, as that
   contains a ca65 version string, and almost always this will be changed!
 
+- ref/<test>.err-ref
+  This is a reference for the resulting ca65 stdout (>) output.
+
+- ref/<test>.err2-ref
+  This is a reference for the resulting ca65 stderr (2>) output.
+
+- ref/<test>.ld65err-ref
+  This is a reference for the resutling ld65 stdout (>) output.
+
+- ref/<test>.ld65err2-ref
+  This is a reference for the resulting ld65 stderr (2>) output.
+
+The following control files can be added to control the tests.
+These files are empty (contents ignored), and only the filename is used:
+
+- control/<test>.err
+  Test is expected to produce an error.
+
+- control/<test>.no-ld65
+  Skip the ld65 step.
+
 
 Note that the resulting .bin file is generated twice: Once with no listing
 file, and once with listing file. This way, one can find out if the listing
 file generation changes anything with the resulting binary output.
-
-
-TODO:
-- add the possibility to test for specific error output that are to be
-  expected
diff --git a/test/asm/listing/ref/108-long-rts.bin-ref b/test/asm/listing/ref/108-long-rts.bin-ref
new file mode 100644
index 000000000..23fa7d31a
--- /dev/null
+++ b/test/asm/listing/ref/108-long-rts.bin-ref
@@ -0,0 +1 @@
+k
\ No newline at end of file
diff --git a/test/asm/val/feature.s b/test/asm/val/feature.s
new file mode 100644
index 000000000..4428cf4c2
--- /dev/null
+++ b/test/asm/val/feature.s
@@ -0,0 +1,147 @@
+; a simple test of every .feature
+
+.export _main
+
+.segment "ZEROPAGE"
+zplabel:
+
+.segment "CODE"
+abslabel:
+
+; exit with 0
+
+_main:
+    ; if any feature needs a runtime test,
+    ; it can be added here.
+    lda #0
+    tax
+    rts
+
+
+.feature addrsize +
+.assert .addrsize(zplabel) = 1, error, ".addrsize 1 expected for ZEROPAGE"
+.assert .addrsize(abslabel) = 2, error, ".addrsize 2 expected for absolute"
+.feature addrsize -
+
+
+.feature at_in_identifiers on
+ident@with@at:
+    rts
+.feature at_in_identifiers off
+
+
+.feature bracket_as_indirect
+    lda [$82],y
+.feature bracket_as_indirect-
+
+
+.feature c_comments
+    lda zplabel /* comment */
+    /* comment */
+/* multiline
+** comment
+*/
+.feature c_comments -
+
+
+.feature dollar_in_identifiers
+ident$with$dollar:
+    rts
+.feature dollar_in_identifiers -
+
+
+.feature dollar_is_pc
+.assert $ = *, error, "dollar_is_pc failure"
+.feature dollar_is_pc -
+
+
+.feature force_range
+    lda #-1
+.feature force_range -
+
+
+.feature labels_without_colons
+labelwithoutcolon
+    jmp labelwithoutcolon
+.feature labels_without_colons -
+
+
+.feature leading_dot_in_identifiers
+.identifierwithdot:
+    rts
+.feature leading_dot_in_identifiers -
+
+
+.feature long_jsr_jmp_rts
+.p816
+    ; long addresses require alternate instruction names JSL, JML without this feature
+    jsr $123456
+    jmp $123456
+; smart + far + long_jsr_jmp_rts will promote rts to rtl
+.smart +
+.proc long_rts : far
+    rts ; should become RTL ($6B) instead of RTS ($60)
+    ; the emitted opcode is not verified by this test,
+    ; see test/asm/listing/108-long-rts
+.endproc
+.smart -
+.p02
+.feature long_jsr_jmp_rts -
+
+
+.feature loose_char_term
+.byte 'a'
+.byte "a"
+.feature loose_char_term -
+
+
+.feature loose_string_term
+.asciiz "string"
+.asciiz 'string'
+.feature loose_string_term -
+
+
+.feature missing_char_term
+    lda #'a
+.feature missing_char_term -
+
+
+.feature org_per_seg
+.segment "RODATA"
+.org $5678
+.assert * = $5678, error, "org_per_seg failed"
+.segment "CODE"
+.org $9ABC
+.assert * = $9ABC, error, "org_per_seg failed"
+.segment "RODATA"
+.assert * = $5678, error, "org_per_seg failed"
+.reloc
+.segment "CODE"
+.assert * = $9ABC, error, "org_per_seg failed"
+.reloc
+.feature org_per_seg -
+
+
+.feature pc_assignment
+* = $1234
+.assert * = $1234, error, "pc_assignment failed"
+.reloc
+.feature pc_assignment -
+
+
+.feature string_escapes
+.asciiz "quote:\""
+.feature string_escapes -
+
+
+.feature ubiquitous_idents
+.macro bit
+    brk
+.endmacro
+    bit
+.feature ubiquitous_idents -
+
+
+.feature underline_in_numbers
+.byte %10_10_10_10
+.feature underline_in_numbers -