Clarification of --rf, --ff options

doc/bcftools.txt

@@ -1901,7 +1901,7 @@ those scenarios.
 *-Q, --min-BQ* 'INT'::
     Minimum base quality for a base to be considered [13]
 
-*    --max-BQ* 'INT'::
+*--max-BQ* 'INT'::
     Caps the base quality to a maximum value [60].  This can be
     particularly useful on technologies that produce overly optimistic
     high qualities, leading to too many false positives or incorrect
@@ -1920,10 +1920,10 @@ those scenarios.
     Ignore RG tags. Treat all reads in one alignment file as one sample.
 
 *--rf, --incl-flags* 'STR'|'INT'::
-    Required flags: skip reads with mask bits unset  [null]
+    Required flags: skip reads with none of the mask bits set  [null]
 
 *--ff, --excl-flags* 'STR'|'INT'::
-    Filter flags: skip reads with mask bits set [UNMAP,SECONDARY,QCFAIL,DUP]
+    Filter flags: skip reads with any of the mask bits set [UNMAP,SECONDARY,QCFAIL,DUP]
 
 *-s, --samples* [^]'LIST'::
     list of sample names. See *<<common_options,Common Options>>*

mpileup.c

@@ -1122,9 +1122,9 @@ static void print_usage(FILE *fp, const mplp_conf_t *mplp)
         "  -r, --regions REG[,...] Comma separated list of regions in which pileup is generated\n"
         "  -R, --regions-file FILE Restrict to regions listed in a file\n"
         "      --ignore-RG         Ignore RG tags (one BAM = one sample)\n"
-        "  --rf, --incl-flags STR|INT  Required flags: skip reads with mask bits unset [%s]\n", tmp_require);
+        "  --rf, --incl-flags STR|INT  Required flags: skip reads with none of the bits set [%s]\n", tmp_require);
     fprintf(fp,
-        "  --ff, --excl-flags STR|INT  Filter flags: skip reads with mask bits set\n"
+        "  --ff, --excl-flags STR|INT  Filter flags: skip reads with any of the bits set\n"
         "                                            [%s]\n", tmp_filter);
     fprintf(fp,
         "  -s, --samples LIST      Comma separated list of samples to include\n"