--- a/app/gapbibl.g
+++ b/app/gapbibl.g
@@ -76,7 +76,7 @@
                   "mscdiffs2010to2020" ] do
       file:= Filename( dir, Concatenation( name, ".txt" ) );
       if file = fail then
-        return false;
+        file := Filename( dir, Concatenation( "no-mscdata", ".txt" ) );;
       fi;
       file:= StringFile( file );
       Add( file, '\n' );
@@ -235,6 +235,12 @@
 ##  </Returns>
 ##
 ##  <Description>
+##  BrowseMSC requires data that can not be distributed as part of the
+##  debian free distribution. You can however get the files mscdata2010.txt,
+##  mscdiffs2000to2010.txt, mscdata2020.txt and mscdiffs2010to2020.txt
+##  from the upstream sources and copy them to /usr/share/gap/pkg/Browse/bibl/.
+##  Putting the files there will enable the functionality.
+##  <P/>
 ##  This function shows the valid MSC codes in a browse table that
 ##  is categorized by the <C>..-XX</C> and the <C>...xx</C> codes.
 ##  (Use <B>X</B> for expanding all categories or <B>x</B> for expanding the
@@ -245,6 +251,7 @@
 ##  If <A>version</A> is given then it must be one of the numbers <M>2010</M>
 ##  or <M>2020</M>, meaning that the MSC2010 or MSC2020 codes are shown;
 ##  the default for <A>version</A> is <M>2020</M>.
+##  <P/>
 ##  </Description>
 ##  </ManSection>
 ##  <#/GAPDoc>
--- /dev/null
+++ b/bibl/no-mscdata.txt
@@ -0,0 +1 @@
+00-XX See the manual for why this is missing in debian.
