Avoid writing "XXX" since it's a conventional "TODO/FIXME" comment

man/rgbasm.5

@@ -2571,9 +2571,9 @@ The stack's number of entries is limited only by the amount of memory in your ma
 .Ic PUSHO
 can also take a comma-separated list of options, to push the current set and apply the argument set at the same time:
 .Bd -literal -offset indent
-PUSHO b.X, g.oOX
-    DB %..XXXX..
-    DW `..ooOOXX
+PUSHO b.#, g.oO#
+    DB %..####..
+    DW `..ooOO##
 POPO
 .Ed
 .Ss Excluding locations from backtraces

src/gfx/process.cpp

@@ -409,10 +409,10 @@ static std::pair<std::vector<size_t>, std::vector<Palette>>
 	}
 
 	auto listColors = [](auto const &list) {
-		static char buf[sizeof(", $XXXX, $XXXX, $XXXX, $XXXX")];
+		static char buf[sizeof(", $xxxx, $xxxx, $xxxx, $xxxx")];
 		char *ptr = buf;
 		for (uint16_t color : list) {
-			ptr += snprintf(ptr, sizeof(", $XXXX"), ", $%04x", color);
+			ptr += snprintf(ptr, sizeof(", $xxxx"), ", $%04x", color);
 		}
 		return &buf[literal_strlen(", ")];
 	};

test/link/cascading-errors.asm

@@ -3,8 +3,8 @@ Zero:
 
 ; Pin the section such that a jr to 0 is out of range
 SECTION "test", ROM0[$1000]
-	;; XXX: the fallback value used is the index of the symbol (in the object file?)
-	;; Is this intended?
+	;; the fallback value for an undefined symbol used to be its index in the object file,
+	;; but is now zero as of RGBLINK v1.0.1
 	dw Bar
 	dw Foo / Bar
 	dw Foo / Zero