diff --git a/analyzer/analyzer.go b/analyzer/analyzer.go
index 4ba1529b..3031f80e 100644
--- a/analyzer/analyzer.go
+++ b/analyzer/analyzer.go
@@ -99,7 +99,7 @@ func runAnalyzer(pass *analysis.Pass) (interface{}, error) {
 			fullMessage := msg
 			if printRuleLocation {
 				fullMessage = fmt.Sprintf("%s: %s (%s:%d)",
-					info.Group, msg, filepath.Base(info.Group.Filename), info.Line)
+					info.Group.Name, msg, filepath.Base(info.Group.Filename), info.Line)
 			}
 			diag := analysis.Diagnostic{
 				Pos:     n.Pos(),
diff --git a/go.mod b/go.mod
index 2d94ee79..65f019e0 100644
--- a/go.mod
+++ b/go.mod
@@ -6,6 +6,6 @@ require (
 	github.com/go-toolsmith/astequal v1.0.0
 	github.com/google/go-cmp v0.5.2
 	github.com/quasilyte/go-ruleguard/dsl v0.3.2
-	github.com/quasilyte/go-ruleguard/rules v0.0.0-20210203162857-b223e0831f88
+	github.com/quasilyte/go-ruleguard/rules v0.0.0-20210428214800-545e0d2e0bf7
 	golang.org/x/tools v0.0.0-20201230224404-63754364767c
 )
diff --git a/go.sum b/go.sum
index 264cbc3b..5da8236e 100644
--- a/go.sum
+++ b/go.sum
@@ -19,6 +19,8 @@ github.com/quasilyte/go-ruleguard/rules v0.0.0-20201231183845-9e62ed36efe1 h1:PX
 github.com/quasilyte/go-ruleguard/rules v0.0.0-20201231183845-9e62ed36efe1/go.mod h1:7JTjp89EGyU1d6XfBiXihJNG37wB2VRkd125Q1u7Plc=
 github.com/quasilyte/go-ruleguard/rules v0.0.0-20210203162857-b223e0831f88 h1:PeTrJiH/dSeruL/Z9Db39NRMwI/yoA3oHCdCkg+Wh8A=
 github.com/quasilyte/go-ruleguard/rules v0.0.0-20210203162857-b223e0831f88/go.mod h1:4cgAphtvu7Ftv7vOT2ZOYhC6CvBxZixcasr8qIOTA50=
+github.com/quasilyte/go-ruleguard/rules v0.0.0-20210428214800-545e0d2e0bf7 h1:cRLFDAB53r5wIkxYvtQUMnn3+B09uZTAOPmefNfVk5I=
+github.com/quasilyte/go-ruleguard/rules v0.0.0-20210428214800-545e0d2e0bf7/go.mod h1:4cgAphtvu7Ftv7vOT2ZOYhC6CvBxZixcasr8qIOTA50=
 github.com/yuin/goldmark v1.1.32/go.mod h1:3hX8gzYuyVAZsxl0MRgGTJEmQBFcNTphYh9decYSb74=
 github.com/yuin/goldmark v1.2.1/go.mod h1:3hX8gzYuyVAZsxl0MRgGTJEmQBFcNTphYh9decYSb74=
 golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
diff --git a/ruleguard/engine.go b/ruleguard/engine.go
index 66a4fd58..3e077bef 100644
--- a/ruleguard/engine.go
+++ b/ruleguard/engine.go
@@ -6,6 +6,7 @@ import (
 	"go/ast"
 	"go/types"
 	"io"
+	"sort"
 	"strings"
 	"sync"
 
@@ -25,6 +26,17 @@ func newEngine() *engine {
 	}
 }
 
+func (e *engine) LoadedGroups() []GoRuleGroup {
+	result := make([]GoRuleGroup, 0, len(e.ruleSet.groups))
+	for _, g := range e.ruleSet.groups {
+		result = append(result, *g)
+	}
+	sort.Slice(result, func(i, j int) bool {
+		return result[i].Name < result[j].Name
+	})
+	return result
+}
+
 func (e *engine) Load(ctx *ParseContext, filename string, r io.Reader) error {
 	config := rulesParserConfig{
 		state: e.state,
diff --git a/ruleguard/gorule.go b/ruleguard/gorule.go
index 35fdc801..d73842ea 100644
--- a/ruleguard/gorule.go
+++ b/ruleguard/gorule.go
@@ -3,7 +3,6 @@ package ruleguard
 import (
 	"fmt"
 	"go/ast"
-	"go/token"
 	"go/types"
 	"regexp"
 
@@ -15,7 +14,7 @@ import (
 type goRuleSet struct {
 	universal *scopedGoRuleSet
 
-	groups map[string]token.Position // To handle redefinitions
+	groups map[string]*GoRuleGroup // To handle redefinitions
 }
 
 type scopedGoRuleSet struct {
@@ -32,7 +31,6 @@ type goCommentRule struct {
 
 type goRule struct {
 	group      *GoRuleGroup
-	filename   string
 	line       int
 	pat        *gogrep.Pattern
 	msg        string
@@ -108,18 +106,18 @@ func cloneRuleSet(rset *goRuleSet) *goRuleSet {
 func mergeRuleSets(toMerge []*goRuleSet) (*goRuleSet, error) {
 	out := &goRuleSet{
 		universal: &scopedGoRuleSet{},
-		groups:    make(map[string]token.Position),
+		groups:    make(map[string]*GoRuleGroup),
 	}
 
 	for _, x := range toMerge {
 		out.universal = appendScopedRuleSet(out.universal, x.universal)
-		for group, pos := range x.groups {
-			if prevPos, ok := out.groups[group]; ok {
-				newRef := fmt.Sprintf("%s:%d", pos.Filename, pos.Line)
-				oldRef := fmt.Sprintf("%s:%d", prevPos.Filename, prevPos.Line)
-				return nil, fmt.Errorf("%s: redefinition of %s(), previously defined at %s", newRef, group, oldRef)
+		for groupName, group := range x.groups {
+			if prevGroup, ok := out.groups[groupName]; ok {
+				newRef := fmt.Sprintf("%s:%d", group.Filename, group.Line)
+				oldRef := fmt.Sprintf("%s:%d", prevGroup.Filename, prevGroup.Line)
+				return nil, fmt.Errorf("%s: redefinition of %s(), previously defined at %s", newRef, groupName, oldRef)
 			}
-			out.groups[group] = pos
+			out.groups[groupName] = group
 		}
 	}
 
diff --git a/ruleguard/parser.go b/ruleguard/parser.go
index 538622af..daf1c882 100644
--- a/ruleguard/parser.go
+++ b/ruleguard/parser.go
@@ -86,7 +86,7 @@ func (p *rulesParser) ParseFile(filename string, r io.Reader) (*goRuleSet, error
 	p.filename = filename
 	p.res = &goRuleSet{
 		universal: &scopedGoRuleSet{},
-		groups:    make(map[string]token.Position),
+		groups:    make(map[string]*GoRuleGroup),
 	}
 
 	parserFlags := parser.ParseComments
@@ -304,7 +304,9 @@ func (p *rulesParser) parseRuleGroup(f *ast.FuncDecl) (err error) {
 	matcher := params[0].Names[0].Name
 
 	p.group = &GoRuleGroup{
-		Name: f.Name.Name,
+		Line:     p.ctx.Fset.Position(f.Name.Pos()).Line,
+		Filename: p.filename,
+		Name:     f.Name.Name,
 	}
 	if p.prefix != "" {
 		p.group.Name = p.prefix + "/" + p.group.Name
@@ -321,10 +323,7 @@ func (p *rulesParser) parseRuleGroup(f *ast.FuncDecl) (err error) {
 	if _, ok := p.res.groups[p.group.Name]; ok {
 		panic(fmt.Sprintf("duplicated function %s after the typecheck", p.group)) // Should never happen
 	}
-	p.res.groups[p.group.Name] = token.Position{
-		Filename: p.filename,
-		Line:     p.ctx.Fset.Position(f.Name.Pos()).Line,
-	}
+	p.res.groups[p.group.Name] = p.group
 
 	p.itab.EnterScope()
 	defer p.itab.LeaveScope()
@@ -477,9 +476,8 @@ func (p *rulesParser) parseRule(matcher string, call *ast.CallExpr) error {
 	}
 
 	proto := goRule{
-		filename: p.filename,
-		line:     p.ctx.Fset.Position(origCall.Pos()).Line,
-		group:    p.group,
+		line:  p.ctx.Fset.Position(origCall.Pos()).Line,
+		group: p.group,
 	}
 
 	// AST patterns for Match() or regexp patterns for MatchComment().
diff --git a/ruleguard/ruleguard.go b/ruleguard/ruleguard.go
index e51b53bc..ccc304e4 100644
--- a/ruleguard/ruleguard.go
+++ b/ruleguard/ruleguard.go
@@ -34,6 +34,11 @@ func (e *Engine) Load(ctx *ParseContext, filename string, r io.Reader) error {
 	return e.impl.Load(ctx, filename, r)
 }
 
+// LoadedGroups returns information about all currently loaded rule groups.
+func (e *Engine) LoadedGroups() []GoRuleGroup {
+	return e.impl.LoadedGroups()
+}
+
 // Run executes all loaded rules on a given file.
 // Matched rules invoke `RunContext.Report()` method.
 //
@@ -87,6 +92,13 @@ type GoRuleGroup struct {
 	// Name is a function name associated with this rule group.
 	Name string
 
+	// Pos is a location where this rule group was defined.
+	Pos token.Position
+
+	// Line is a source code line number inside associated file.
+	// A pair of Filename:Line form a conventional location string.
+	Line int
+
 	// Filename is a file that defined this rule group.
 	Filename string
 
diff --git a/ruleguard/runner.go b/ruleguard/runner.go
index 3efb5c3c..e6fc8c24 100644
--- a/ruleguard/runner.go
+++ b/ruleguard/runner.go
@@ -199,7 +199,7 @@ func (rr *rulesRunner) reject(rule goRule, reason string, m matchData) {
 
 	pos := rr.ctx.Fset.Position(m.Node().Pos())
 	rr.ctx.DebugPrint(fmt.Sprintf("%s:%d: [%s:%d] rejected by %s",
-		pos.Filename, pos.Line, filepath.Base(rule.filename), rule.line, reason))
+		pos.Filename, pos.Line, filepath.Base(rule.group.Filename), rule.line, reason))
 
 	values := make([]gogrep.CapturedNode, len(m.CaptureList()))
 	copy(values, m.CaptureList())