diff --git a/tests/t1310-listcon.sh b/tests/t1310-listcon.sh
index 9e44def..4294508 100755
--- a/tests/t1310-listcon.sh
+++ b/tests/t1310-listcon.sh
@@ -65,6 +65,47 @@ test_todo_session 'listcon with project' <<EOF
 @garden
 EOF
 
+cat > todo.txt <<EOF
+(B) +math (@school or @home) integrate @x and @y
+(C) say thanks @GinaTrapani w:@OtherContributors
+stop
+EOF
+test_todo_session 'listcon with default configuration' <<EOF
+>>> todo.sh listcon
+@GinaTrapani
+@home)
+@x
+@y
+EOF
+test_todo_session 'listcon limiting to multi-character sequences' <<EOF
+>>> TODOTXT_SIGIL_VALID_PATTERN='.\{2,\}' todo.sh listcon
+@GinaTrapani
+@home)
+EOF
+test_todo_session 'listcon allowing w: marker before contexts' <<EOF
+>>> TODOTXT_SIGIL_BEFORE_PATTERN='\(w:\)\{0,1\}' todo.sh listcon
+@GinaTrapani
+@OtherContributors
+@home)
+@x
+@y
+EOF
+test_todo_session 'listcon allowing parentheses around contexts' <<EOF
+>>> TODOTXT_SIGIL_BEFORE_PATTERN='(\{0,1\}' TODOTXT_SIGIL_AFTER_PATTERN=')\{0,1\}' todo.sh listcon
+@GinaTrapani
+@home
+@school
+@x
+@y
+EOF
+test_todo_session 'listcon with all customizations combined' <<EOF
+>>> TODOTXT_SIGIL_VALID_PATTERN='.\{2,\}' TODOTXT_SIGIL_BEFORE_PATTERN='\(w:\)\{0,1\}\((\)\{0,1\}' TODOTXT_SIGIL_AFTER_PATTERN=')\{0,1\}' todo.sh listcon
+@GinaTrapani
+@OtherContributors
+@home
+@school
+EOF
+
 cat > todo.txt <<EOF
 @con01 -- Some context 1 task
 EOF
diff --git a/tests/t1320-listproj.sh b/tests/t1320-listproj.sh
index 5f2f6fe..56bcdc3 100755
--- a/tests/t1320-listproj.sh
+++ b/tests/t1320-listproj.sh
@@ -75,6 +75,33 @@ test_todo_session 'listproj with context' <<EOF
 +sunflowers
 EOF
 
+cat > todo.txt <<EOF
+(B) give a +1 to this project
+(C) notice the sunflowers +sunflowers [+gardening] [+landscape]
+stop
+EOF
+test_todo_session 'listproj with default configuration' <<EOF
+>>> todo.sh listproj
++1
++sunflowers
+EOF
+test_todo_session 'listproj limiting to alphabetic characters' <<EOF
+>>> TODOTXT_SIGIL_VALID_PATTERN='[a-zA-Z]\{1,\}' todo.sh listproj
++sunflowers
+EOF
+test_todo_session 'listproj allowing brackets around projects' <<EOF
+>>> TODOTXT_SIGIL_BEFORE_PATTERN='\[\{0,1\}' TODOTXT_SIGIL_AFTER_PATTERN='\]\{0,1\}' todo.sh listproj
++1
++gardening
++landscape
++sunflowers
+EOF
+
+cat > todo.txt <<EOF
+(B) smell the uppercase Roses +roses @outside +shared
+(C) notice the sunflowers +sunflowers @garden +shared +landscape
+stop
+EOF
 TEST_TODO_CUSTOM=todo-custom.cfg
 cat todo.cfg > "$TEST_TODO_CUSTOM"
 cat >> "$TEST_TODO_CUSTOM" <<'EOF'
diff --git a/todo.sh b/todo.sh
index 39a6ee3..671ee48 100755
--- a/todo.sh
+++ b/todo.sh
@@ -149,6 +149,9 @@ help()
 		    TODOTXT_SORT_COMMAND="sort ..." customize list output
 		    TODOTXT_FINAL_FILTER="sed ..."  customize list after color, P@+ hiding
 		    TODOTXT_SOURCEVAR=\$DONE_FILE   use another source for listcon, listproj
+		    TODOTXT_SIGIL_BEFORE_PATTERN="" optionally allow chars preceding +p / @c
+		    TODOTXT_SIGIL_VALID_PATTERN=.*  tweak the allowed chars for +p and @c
+		    TODOTXT_SIGIL_AFTER_PATTERN=""  optionally allow chars after +p / @c
 
 
 	EndVerboseHelp
@@ -620,6 +623,9 @@ TODOTXT_SORT_COMMAND=${TODOTXT_SORT_COMMAND:-env LC_COLLATE=C sort -f -k2}
 TODOTXT_DISABLE_FILTER=${TODOTXT_DISABLE_FILTER:-}
 TODOTXT_FINAL_FILTER=${TODOTXT_FINAL_FILTER:-cat}
 TODOTXT_GLOBAL_CFG_FILE=${TODOTXT_GLOBAL_CFG_FILE:-/etc/todo/config}
+TODOTXT_SIGIL_BEFORE_PATTERN=${TODOTXT_SIGIL_BEFORE_PATTERN:-}	# Allow any other non-whitespace entity before +project and @context; should be an optional match; example: \(w:\)\{0,1\} to allow w:@context.
+TODOTXT_SIGIL_VALID_PATTERN=${TODOTXT_SIGIL_VALID_PATTERN:-.*}	# Limit the valid characters (from the default any non-whitespace sequence) for +project and @context; example: [a-zA-Z]\{3,\} to only allow alphabetic ones that are at least three characters long.
+TODOTXT_SIGIL_AFTER_PATTERN=${TODOTXT_SIGIL_AFTER_PATTERN:-}	# Allow any other non-whitespace entity after +project and @context; should be an optional match; example: )\{0,1\} to allow (with the corresponding TODOTXT_SIGIL_BEFORE_PATTERN) enclosing in parentheses.
 
 # Export all TODOTXT_* variables
 export "${!TODOTXT_@}"
@@ -1037,7 +1043,13 @@ listWordsWithSigil()
 
     FILE=$TODO_FILE
     [ "$TODOTXT_SOURCEVAR" ] && eval "FILE=$TODOTXT_SOURCEVAR"
-    eval "$(filtercommand 'cat "${FILE[@]}"' '' "$@")" | grep -o "[^ ]*${sigil}[^ ]\\+" | grep "^$sigil" | sort -u
+	eval "$(filtercommand 'cat "${FILE[@]}"' '' "$@")" \
+		| grep -o "[^ ]*${sigil}[^ ]\\+" \
+		| sed -n \
+			-e "s#^${TODOTXT_SIGIL_BEFORE_PATTERN//#/\\#}##" \
+			-e "s#${TODOTXT_SIGIL_AFTER_PATTERN//#/\\#}\$##" \
+			-e "/^${sigil}${TODOTXT_SIGIL_VALID_PATTERN//\//\\/}$/p" \
+		| sort -u
 }
 
 export -f cleaninput getPrefix getTodo getNewtodo shellquote filtercommand _list listWordsWithSigil getPadding _format die