diff --git a/converter.go b/converter.go
new file mode 100644
index 0000000..6005f5b
--- /dev/null
+++ b/converter.go
@@ -0,0 +1,116 @@
+package tagliatelle
+
+import (
+	"fmt"
+	"strings"
+
+	"github.com/ettle/strcase"
+)
+
+// https://github.com/dominikh/go-tools/blob/v0.5.1/config/config.go#L167-L175
+//
+//nolint:gochecknoglobals // For now I'll accept this, but I think will refactor to use a structure.
+var staticcheckInitialisms = map[string]bool{
+	"AMQP": true,
+	"DB":   true,
+	"GID":  true,
+	"LHS":  false,
+	"RHS":  false,
+	"RTP":  true,
+	"SIP":  true,
+	"TS":   true,
+}
+
+// Converter is the signature of a case converter.
+type Converter func(s string) string
+
+// ConverterCallback allows to abstract `getSimpleConverter` and `ruleToConverter`.
+type ConverterCallback func() (Converter, error)
+
+func getSimpleConverter(c string) (Converter, error) {
+	switch c {
+	case "camel":
+		return strcase.ToCamel, nil
+	case "pascal":
+		return strcase.ToPascal, nil
+	case "kebab":
+		return strcase.ToKebab, nil
+	case "snake":
+		return strcase.ToSnake, nil
+	case "goCamel":
+		return strcase.ToGoCamel, nil
+	case "goPascal":
+		return strcase.ToGoPascal, nil
+	case "goKebab":
+		return strcase.ToGoKebab, nil
+	case "goSnake":
+		return strcase.ToGoSnake, nil
+	case "upperSnake":
+		return strcase.ToSNAKE, nil
+	case "header":
+		return toHeader, nil
+	case "upper":
+		return strings.ToUpper, nil
+	case "lower":
+		return strings.ToLower, nil
+	default:
+		return nil, fmt.Errorf("unsupported case: %s", c)
+	}
+}
+
+func toHeader(s string) string {
+	return strcase.ToCase(s, strcase.TitleCase, '-')
+}
+
+func ruleToConverter(rule ExtendedRule) (Converter, error) {
+	if rule.ExtraInitialisms {
+		for k, v := range staticcheckInitialisms {
+			if _, found := rule.InitialismOverrides[k]; found {
+				continue
+			}
+
+			rule.InitialismOverrides[k] = v
+		}
+	}
+
+	caser := strcase.NewCaser(strings.HasPrefix(rule.Case, "go"), rule.InitialismOverrides, nil)
+
+	switch strings.ToLower(strings.TrimPrefix(rule.Case, "go")) {
+	case "camel":
+		return caser.ToCamel, nil
+
+	case "pascal":
+		return caser.ToPascal, nil
+
+	case "kebab":
+		return caser.ToKebab, nil
+
+	case "snake":
+		return caser.ToSnake, nil
+
+	case "uppersnake":
+		return caser.ToSNAKE, nil
+
+	case "header":
+		return toHeaderCase(caser), nil
+
+	case "upper":
+		return func(s string) string {
+			return caser.ToCase(s, strcase.UpperCase, 0)
+		}, nil
+
+	case "lower":
+		return func(s string) string {
+			return caser.ToCase(s, strcase.LowerCase, 0)
+		}, nil
+
+	default:
+		return nil, fmt.Errorf("unsupported case: %s", rule.Case)
+	}
+}
+
+func toHeaderCase(caser *strcase.Caser) Converter {
+	return func(s string) string {
+		return caser.ToCase(s, strcase.TitleCase, '-')
+	}
+}
diff --git a/go.mod b/go.mod
index 60fb726..b559e70 100644
--- a/go.mod
+++ b/go.mod
@@ -3,7 +3,7 @@ module github.com/ldez/tagliatelle
 go 1.22.0
 
 require (
-	github.com/ettle/strcase v0.2.0
+	github.com/ettle/strcase v0.2.1-0.20230114185658-e5db6a6becf3
 	github.com/hashicorp/go-immutable-radix/v2 v2.1.0
 	golang.org/x/tools v0.27.0
 )
diff --git a/go.sum b/go.sum
index cfee3e8..39de705 100644
--- a/go.sum
+++ b/go.sum
@@ -1,5 +1,5 @@
-github.com/ettle/strcase v0.2.0 h1:fGNiVF21fHXpX1niBgk0aROov1LagYsOwV/xqKDKR/Q=
-github.com/ettle/strcase v0.2.0/go.mod h1:DajmHElDSaX76ITe3/VHVyMin4LWSJN5Z909Wp+ED1A=
+github.com/ettle/strcase v0.2.1-0.20230114185658-e5db6a6becf3 h1:UveVPOxnOkBoelw2vLZTm+L0Z7fe/nz5d6JlY+A3QdE=
+github.com/ettle/strcase v0.2.1-0.20230114185658-e5db6a6becf3/go.mod h1:DajmHElDSaX76ITe3/VHVyMin4LWSJN5Z909Wp+ED1A=
 github.com/google/go-cmp v0.6.0 h1:ofyhxvXcZhMsU5ulbFiLKl/XBFqE1GSq7atu8tAmTRI=
 github.com/google/go-cmp v0.6.0/go.mod h1:17dUlkBOakJ0+DkrSSNjCkIjxS6bF9zb3elmeNGIjoY=
 github.com/hashicorp/go-immutable-radix/v2 v2.1.0 h1:CUW5RYIcysz+D3B+l1mDeXrQ7fUvGGCwJfdASSzbrfo=
diff --git a/readme.md b/readme.md
index f343387..cb7e33a 100644
--- a/readme.md
+++ b/readme.md
@@ -97,15 +97,14 @@ type Foo struct {
 }
 ```
 
-## What this tool is about
+## What this linter is about
 
-This tool is about validating tags according to rules you define.
-The tool also allows to fix tags according to the rules you defined.
+This linter is about validating tags according to rules you define.
+The linter also allows to fix tags according to the rules you defined.
 
-This tool is not intended to validate the fact a tag in valid or not.
-To do that, you can use `go vet`, or use [golangci-lint](https://golangci-lint.run) ["go vet"](https://golangci-lint.run/usage/linters/#govet) linter.
+This linter is not intended to validate the fact a tag in valid or not.
 
-## How to use the tool
+## How to use the linter
 
 ### As a golangci-lint linter
 
@@ -114,9 +113,9 @@ Define the rules, you want via your [golangci-lint](https://golangci-lint.run) c
 ```yaml
 linters-settings:
   tagliatelle:
-    # Check the struct tag name case.
+    # Checks the struct tag name case.
     case:
-      # Define the association between tag name and case.
+      # Defines the association between tag name and case.
       # Any struct tag name can be used.
       # Supported string cases:
       # - `camel`
@@ -142,7 +141,38 @@ linters-settings:
         env: upperSnake
         envconfig: upperSnake
         whatever: snake
-      # Use the struct field name to check the name of the struct tag.
+      # Defines the association between tag name and case.
+      # Important: the `extended-rules` overrides `rules`.
+      # Default: empty
+      extended-rules:
+        json:
+          # Supported string cases:
+          # - `camel`
+          # - `pascal`
+          # - `kebab`
+          # - `snake`
+          # - `upperSnake`
+          # - `goCamel`
+          # - `goPascal`
+          # - `goKebab`
+          # - `goSnake`
+          # - `header`
+          # - `lower`
+          # - `header`
+          #
+          # Required
+          case: camel
+          # Adds 'AMQP', 'DB', 'GID', 'RTP', 'SIP', 'TS' to initialisms,
+          # and removes 'LHS', 'RHS' from initialisms.
+          # Default: true
+          extra-initialisms: false
+          # Defines initialism additions and overrides.
+          # Default: empty
+          initialism-overrides:
+            DB: true # add a new initialism
+            LHS: false # disable a default initialism.
+            # ...
+      # Uses the struct field name to check the name of the struct tag.
       # Default: false
       use-field-name: true
       # The field names to ignore.
@@ -161,6 +191,9 @@ linters-settings:
           rules:
             json: snake
             xml: pascal
+          # Default: empty or the same as the default/root configuration.
+          extended-rules:
+            # same options as the base `extended-rules`.
           # Default: false (WARNING: it doesn't follow the default/root configuration)
           use-field-name: true
           # The field names to ignore.
@@ -171,6 +204,7 @@ linters-settings:
           # Ignore the package (takes precedence over all other configurations).
           # Default: false
           ignore: true
+
 ```
 
 #### Examples
@@ -251,9 +285,9 @@ Here are the default rules for the well known and used tags, when using tagliate
 
 ### Custom Rules
 
-The tool is not limited to the tags used in example, you can use it to validate any tag.
+The linter is not limited to the tags used in example, **you can use it to validate any tag**.
 
-You can add your own tag, for example `whatever` and tells the tool you want to use `kebab`.
+You can add your own tag, for example `whatever` and tells the linter you want to use `kebab`.
 
 This option is only available via [golangci-lint](https://golangci-lint.run).
 
diff --git a/tagliatelle.go b/tagliatelle.go
index aa2b24b..99c7da2 100644
--- a/tagliatelle.go
+++ b/tagliatelle.go
@@ -13,7 +13,6 @@ import (
 	"slices"
 	"strings"
 
-	"github.com/ettle/strcase"
 	iradix "github.com/hashicorp/go-immutable-radix/v2"
 	"golang.org/x/tools/go/analysis"
 	"golang.org/x/tools/go/analysis/passes/inspect"
@@ -35,26 +34,32 @@ type Overrides struct {
 // Base shared configuration between rules.
 type Base struct {
 	Rules         map[string]string
+	ExtendedRules map[string]ExtendedRule
 	UseFieldName  bool
 	IgnoredFields []string
 	Ignore        bool
 }
 
+// ExtendedRule allows to customize rules.
+type ExtendedRule struct {
+	Case                string
+	ExtraInitialisms    bool
+	InitialismOverrides map[string]bool
+}
+
 // New creates an analyzer.
 func New(config Config) *analysis.Analyzer {
 	return &analysis.Analyzer{
 		Name: "tagliatelle",
 		Doc:  "Checks the struct tags.",
 		Run: func(pass *analysis.Pass) (any, error) {
-			if len(config.Rules) == 0 && len(config.Overrides) == 0 {
+			if len(config.Rules) == 0 && len(config.ExtendedRules) == 0 && len(config.Overrides) == 0 {
 				return nil, nil
 			}
 
 			return run(pass, config)
 		},
-		Requires: []*analysis.Analyzer{
-			inspect.Analyzer,
-		},
+		Requires: []*analysis.Analyzer{inspect.Analyzer},
 	}
 }
 
@@ -109,60 +114,74 @@ func analyze(pass *analysis.Pass, config Base, n *ast.StructType, field *ast.Fie
 		return
 	}
 
+	cleanRules(config)
+
 	if slices.Contains(config.IgnoredFields, fieldName) {
 		return
 	}
 
+	for key, extRule := range config.ExtendedRules {
+		report(pass, config, key, extRule.Case, fieldName, n, field, func() (Converter, error) {
+			return ruleToConverter(extRule)
+		})
+	}
+
 	for key, convName := range config.Rules {
-		if convName == "" {
-			continue
-		}
+		report(pass, config, key, convName, fieldName, n, field, func() (Converter, error) {
+			return getSimpleConverter(convName)
+		})
+	}
+}
 
-		value, flags, ok := lookupTagValue(field.Tag, key)
-		if !ok {
-			// skip when no struct tag for the key
-			continue
-		}
+func report(pass *analysis.Pass, config Base, key, convName, fieldName string, n *ast.StructType, field *ast.Field, fn ConverterCallback) {
+	if convName == "" {
+		return
+	}
 
-		if value == "-" {
-			// skip when skipped :)
-			continue
-		}
+	value, flags, ok := lookupTagValue(field.Tag, key)
+	if !ok {
+		// skip when no struct tag for the key
+		return
+	}
 
-		// TODO(ldez): need to be rethink.
-		// tagliatelle should try to remain neutral in terms of format.
-		if key == "xml" && strings.ContainsAny(value, ">:") {
-			// ignore XML names than contains path
-			continue
-		}
+	if value == "-" {
+		// skip when skipped :)
+		return
+	}
 
-		// TODO(ldez): need to be rethink.
-		// This is an exception because of a bug.
-		// https://github.com/ldez/tagliatelle/issues/8
-		// For now, tagliatelle should try to remain neutral in terms of format.
-		if hasTagFlag(flags, "inline") {
-			// skip for inline children (no name to lint)
-			continue
-		}
+	// TODO(ldez): need to be rethink.
+	// tagliatelle should try to remain neutral in terms of format.
+	if key == "xml" && strings.ContainsAny(value, ">:") {
+		// ignore XML names than contains path
+		return
+	}
 
-		if value == "" {
-			value = fieldName
-		}
+	// TODO(ldez): need to be rethink.
+	// This is an exception because of a bug.
+	// https://github.com/ldez/tagliatelle/issues/8
+	// For now, tagliatelle should try to remain neutral in terms of format.
+	if hasTagFlag(flags, "inline") {
+		// skip for inline children (no name to lint)
+		return
+	}
 
-		converter, err := getConverter(convName)
-		if err != nil {
-			pass.Reportf(n.Pos(), "%s(%s): %v", key, convName, err)
-			continue
-		}
+	if value == "" {
+		value = fieldName
+	}
 
-		expected := value
-		if config.UseFieldName {
-			expected = fieldName
-		}
+	converter, err := fn()
+	if err != nil {
+		pass.Reportf(n.Pos(), "%s(%s): %v", key, convName, err)
+		return
+	}
 
-		if value != converter(expected) {
-			pass.Reportf(field.Tag.Pos(), "%s(%s): got '%s' want '%s'", key, convName, value, converter(expected))
-		}
+	expected := value
+	if config.UseFieldName {
+		expected = fieldName
+	}
+
+	if value != converter(expected) {
+		pass.Reportf(field.Tag.Pos(), "%s(%s): got '%s' want '%s'", key, convName, value, converter(expected))
 	}
 }
 
@@ -222,48 +241,14 @@ func hasTagFlag(flags []string, query string) bool {
 	return false
 }
 
-func getConverter(c string) (func(s string) string, error) {
-	switch c {
-	case "camel":
-		return strcase.ToCamel, nil
-	case "pascal":
-		return strcase.ToPascal, nil
-	case "kebab":
-		return strcase.ToKebab, nil
-	case "snake":
-		return strcase.ToSnake, nil
-	case "goCamel":
-		return strcase.ToGoCamel, nil
-	case "goPascal":
-		return strcase.ToGoPascal, nil
-	case "goKebab":
-		return strcase.ToGoKebab, nil
-	case "goSnake":
-		return strcase.ToGoSnake, nil
-	case "header":
-		return toHeader, nil
-	case "upper":
-		return strings.ToUpper, nil
-	case "upperSnake":
-		return strcase.ToSNAKE, nil
-	case "lower":
-		return strings.ToLower, nil
-	default:
-		return nil, fmt.Errorf("unsupported case: %s", c)
-	}
-}
-
-func toHeader(s string) string {
-	return strcase.ToCase(s, strcase.TitleCase, '-')
-}
-
 func createRadixTree(config Config, modPath string) *iradix.Tree[Base] {
 	r := iradix.New[Base]()
 
 	defaultRule := Base{
-		Rules:        copyMap(config.Rules),
-		UseFieldName: config.UseFieldName,
-		Ignore:       config.Ignore,
+		Rules:         maps.Clone(config.Rules),
+		ExtendedRules: maps.Clone(config.ExtendedRules),
+		UseFieldName:  config.UseFieldName,
+		Ignore:        config.Ignore,
 	}
 
 	defaultRule.IgnoredFields = append(defaultRule.IgnoredFields, config.IgnoredFields...)
@@ -284,13 +269,21 @@ func createRadixTree(config Config, modPath string) *iradix.Tree[Base] {
 		}
 
 		// Copy the rules from the base.
-		c.Rules = copyMap(config.Rules)
+		c.Rules = maps.Clone(config.Rules)
 
 		// Overrides the rule from the base.
 		for k, v := range override.Rules {
 			c.Rules[k] = v
 		}
 
+		// Copy the extended rules from the base.
+		c.ExtendedRules = maps.Clone(config.ExtendedRules)
+
+		// Overrides the extended rule from the base.
+		for k, v := range override.ExtendedRules {
+			c.ExtendedRules[k] = v
+		}
+
 		key := path.Join(modPath, override.Package)
 		if filepath.Base(modPath) == override.Package {
 			key = modPath
@@ -302,8 +295,8 @@ func createRadixTree(config Config, modPath string) *iradix.Tree[Base] {
 	return r
 }
 
-func copyMap[K, V comparable](m map[K]V) map[K]V {
-	c := make(map[K]V)
-	maps.Copy(c, m)
-	return c
+func cleanRules(config Base) {
+	for k := range config.ExtendedRules {
+		delete(config.Rules, k)
+	}
 }
diff --git a/tagliatelle_test.go b/tagliatelle_test.go
index a1a5e97..7d944dc 100644
--- a/tagliatelle_test.go
+++ b/tagliatelle_test.go
@@ -155,6 +155,58 @@ func TestAnalyzer(t *testing.T) {
 				}},
 			},
 		},
+		{
+			desc:     "Extended rules",
+			dir:      "extended",
+			patterns: []string{"example.com/fake/extended/..."},
+			cfg: tagliatelle.Config{
+				Base: tagliatelle.Base{
+					ExtendedRules: map[string]tagliatelle.ExtendedRule{
+						"json": {
+							Case: "goCamel",
+							InitialismOverrides: map[string]bool{
+								"DB":  true,
+								"URL": true,
+							},
+						},
+						"sample": {
+							Case: "goCamel",
+						},
+						"yaml": {
+							Case: "goSnake",
+							InitialismOverrides: map[string]bool{
+								"DB": true,
+							},
+						},
+					},
+					UseFieldName: true,
+				},
+			},
+		},
+		{
+			desc:     "Extended rules overrides base rules",
+			dir:      "extended",
+			patterns: []string{"example.com/fake/extended/..."},
+			cfg: tagliatelle.Config{
+				Base: tagliatelle.Base{
+					Rules: map[string]string{
+						"json": "snake",
+					},
+					ExtendedRules: map[string]tagliatelle.ExtendedRule{
+						"json": {
+							Case: "goCamel",
+							InitialismOverrides: map[string]bool{
+								"DB": true,
+							},
+						},
+						"sample": {
+							Case: "goCamel",
+						},
+					},
+					UseFieldName: true,
+				},
+			},
+		},
 	}
 
 	t.Setenv("GOPROXY", "off")
diff --git a/testdata/src/example.com/extended/extended.go b/testdata/src/example.com/extended/extended.go
new file mode 100644
index 0000000..dad0972
--- /dev/null
+++ b/testdata/src/example.com/extended/extended.go
@@ -0,0 +1,21 @@
+package extended
+
+type Foo struct {
+	MyDB  string `json:"myDb"` // want `json\(goCamel\): got 'myDb' want 'myDB'`
+	Dbase string `json:"dbase"`
+
+	VirtualIPv4 string `yaml:"virtual_i_pv4"` // just to illustrate the current limitations: I think that 'virtual_ip_v4' is expected.
+	VirtualIPv6 string `json:"virtualIPv6"`
+
+	DocURLs string `json:"docUrLs"` // just to illustrate the current limitations: I think that 'docURLs' is expected.
+}
+
+type Bar struct {
+	MyDB  string `json:"myDB"`
+	Dbase string `json:"dbase"`
+}
+
+type FooBar struct {
+	MyDB  string `sample:"myDb"` // base rule.
+	Dbase string `sample:"dbase"`
+}
diff --git a/testdata/src/example.com/extended/go.mod b/testdata/src/example.com/extended/go.mod
new file mode 100644
index 0000000..a52986f
--- /dev/null
+++ b/testdata/src/example.com/extended/go.mod
@@ -0,0 +1,3 @@
+module example.com/fake/extended
+
+go 1.22.0