diff --git a/src/main/resources/org/eolang/lints/names/invalid-name-notation.xsl b/src/main/resources/org/eolang/lints/names/invalid-name-notation.xsl
new file mode 100644
index 000000000..a6eae13f6
--- /dev/null
+++ b/src/main/resources/org/eolang/lints/names/invalid-name-notation.xsl
@@ -0,0 +1,34 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!--
+ * SPDX-FileCopyrightText: Copyright (c) 2016-2025 Objectionary.com
+ * SPDX-License-Identifier: MIT
+-->
+<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform" xmlns:eo="https://www.eolang.org" version="2.0" id="invalid-name-notation">
+  <xsl:import href="/org/eolang/funcs/lineno.xsl"/>
+  <xsl:import href="/org/eolang/funcs/defect-context.xsl"/>
+  <xsl:import href="/org/eolang/funcs/special-name.xsl"/>
+  <xsl:output encoding="UTF-8" method="xml"/>
+  <xsl:variable name="pattern" select="'^[a-z]+(-[a-z]+)*$'"/>
+  <xsl:template match="/">
+    <defects>
+      <xsl:for-each select="//o[@name and not(eo:special(@name)) and not(matches(@name, $pattern))]">
+        <defect>
+          <xsl:variable name="line" select="eo:lineno(@line)"/>
+          <xsl:attribute name="line">
+            <xsl:value-of select="$line"/>
+          </xsl:attribute>
+          <xsl:if test="$line = '0'">
+            <xsl:attribute name="context">
+              <xsl:value-of select="eo:defect-context(.)"/>
+            </xsl:attribute>
+          </xsl:if>
+          <xsl:attribute name="severity">warning</xsl:attribute>
+          <xsl:text>Object name "</xsl:text>
+          <xsl:value-of select="@name"/>
+          <xsl:text>" doesn’t match the regular expression </xsl:text>
+          <xsl:value-of select="$pattern"/>
+        </defect>
+      </xsl:for-each>
+    </defects>
+  </xsl:template>
+</xsl:stylesheet>
diff --git a/src/main/resources/org/eolang/motives/names/invalid-name-notation.md b/src/main/resources/org/eolang/motives/names/invalid-name-notation.md
new file mode 100644
index 000000000..c9006e952
--- /dev/null
+++ b/src/main/resources/org/eolang/motives/names/invalid-name-notation.md
@@ -0,0 +1,23 @@
+# Invalid name notation
+
+The object name must match the regular expression `[a-z]+(-[a-z]+)*`.
+Basically, it should follow kebab-case style,
+but using only Latin letters - no digits or other characters.
+
+Incorrect:
+
+```eo
+# App.
+[] > mainApp
+  foo > x1
+  bar > y_
+```
+
+Correct:
+
+```eo
+# App.
+[] > main-app
+  foo > x
+  bar > y
+```
diff --git a/src/test/resources/org/eolang/lints/canonical.eo b/src/test/resources/org/eolang/lints/canonical.eo
index 098db4502..01edd2b82 100644
--- a/src/test/resources/org/eolang/lints/canonical.eo
+++ b/src/test/resources/org/eolang/lints/canonical.eo
@@ -16,8 +16,8 @@
         *
           x.put 2
           while
-            x.as-number.lt 6 > [i1] >>
-            [i] >>
+            x.as-number.lt 6 > [i] >>
+            [j] >>
               seq > @
                 *
                   QQ.io.stdout
diff --git a/src/test/resources/org/eolang/lints/packs/single/invalid-name-notation/allows-good-names.yaml b/src/test/resources/org/eolang/lints/packs/single/invalid-name-notation/allows-good-names.yaml
new file mode 100644
index 000000000..e82abc5f0
--- /dev/null
+++ b/src/test/resources/org/eolang/lints/packs/single/invalid-name-notation/allows-good-names.yaml
@@ -0,0 +1,12 @@
+# SPDX-FileCopyrightText: Copyright (c) 2016-2025 Objectionary.com
+# SPDX-License-Identifier: MIT
+---
+sheets:
+  - /org/eolang/lints/names/invalid-name-notation.xsl
+asserts:
+  - /defects[count(defect[@severity='warning'])=0]
+input: |
+  # App.
+  [] > main-app
+    foo > x
+    bar > y
diff --git a/src/test/resources/org/eolang/lints/packs/single/invalid-name-notation/allows-special-names.yaml b/src/test/resources/org/eolang/lints/packs/single/invalid-name-notation/allows-special-names.yaml
new file mode 100644
index 000000000..bcab23373
--- /dev/null
+++ b/src/test/resources/org/eolang/lints/packs/single/invalid-name-notation/allows-special-names.yaml
@@ -0,0 +1,14 @@
+# SPDX-FileCopyrightText: Copyright (c) 2016-2025 Objectionary.com
+# SPDX-License-Identifier: MIT
+---
+sheets:
+  - /org/eolang/lints/names/invalid-name-notation.xsl
+asserts:
+  - /defects[count(defect[@severity='warning'])=0]
+input: |
+  # App.
+  [] > app
+    x > f
+      [] >>
+    foo > @
+    [] > baz ?
diff --git a/src/test/resources/org/eolang/lints/packs/single/invalid-name-notation/catches-invalid-names.yaml b/src/test/resources/org/eolang/lints/packs/single/invalid-name-notation/catches-invalid-names.yaml
new file mode 100644
index 000000000..f09196ec6
--- /dev/null
+++ b/src/test/resources/org/eolang/lints/packs/single/invalid-name-notation/catches-invalid-names.yaml
@@ -0,0 +1,15 @@
+# SPDX-FileCopyrightText: Copyright (c) 2016-2025 Objectionary.com
+# SPDX-License-Identifier: MIT
+---
+sheets:
+  - /org/eolang/lints/names/invalid-name-notation.xsl
+asserts:
+  - /defects[count(defect[@severity='warning'])=3]
+  - /defects/defect[@line='2']
+  - /defects/defect[@line='3']
+  - /defects/defect[@line='4']
+input: |
+  # App.
+  [] > mainApp
+    foo > x1
+    bar > y_