tachiyomi/app/src/main/res/menu/chapters_mat_single.xml

<?xml version="1.0" encoding="utf-8"?>

<menu xmlns:android="http://schemas.android.com/apk/res/android">

    <item android:id="@+id/action_mark_as_read"
        android:title="@string/action_mark_as_read" />

    <item android:id="@+id/action_mark_as_unread"
        android:title="@string/action_mark_as_unread" />

    <item android:id="@+id/action_bookmark"
        android:title="@string/action_bookmark"
        android:visible="true" />

    <item android:id="@+id/action_remove_bookmark"
        android:title="@string/action_remove_bookmark"
        android:visible="true" />
</menu>