diff --git a/.github/generate.py b/.github/generate.py
index a1b7626..4dbbbae 100755
--- a/.github/generate.py
+++ b/.github/generate.py
@@ -81,7 +81,7 @@ class ColumnDef:
     params: List["LuaParam"] = field(default_factory=list)
 
 
-HL = [LuaParam("highlight", "string|fun", "Highlight group")]
+HL = [LuaParam("highlight", "string|fun(value: string): string", "Highlight group, or function that returns a highlight group")]
 TIME = [
     LuaParam("format", "string", "Format string (see :help strftime)"),
 ]
@@ -91,7 +91,8 @@ COL_DEFS = [
         "*",
         False,
         "The type of the entry (file, directory, link, etc)",
-        HL + [LuaParam("icons", "table<string, string>", "Mapping of entry type to icon")],
+        HL
+        + [LuaParam("icons", "table<string, string>", "Mapping of entry type to icon")],
     ),
     ColumnDef(
         "icon",
@@ -101,7 +102,9 @@ COL_DEFS = [
         HL + [],
     ),
     ColumnDef("size", "files, ssh", False, "The size of the file", HL + []),
-    ColumnDef("permissions", "files, ssh", True, "Access permissions of the file", HL + []),
+    ColumnDef(
+        "permissions", "files, ssh", True, "Access permissions of the file", HL + []
+    ),
     ColumnDef("ctime", "files", False, "Change timestamp of the file", HL + TIME + []),
     ColumnDef(
         "mtime", "files", False, "Last modified time of the file", HL + TIME + []
@@ -140,6 +143,12 @@ def get_highlights_vimdoc() -> "VimdocSection":
 
 def get_columns_vimdoc() -> "VimdocSection":
     section = VimdocSection("Columns", "oil-columns", ["\n"])
+    section.body.extend(
+        wrap(
+            'Columns can be specified as a string to use default arguments (e.g. `"icon"`), or as a table to pass parameters (e.g. `{"size", highlight = "Special"}`)'
+        )
+    )
+    section.body.append('\n')
     for col in COL_DEFS:
         section.body.append(leftright(col.name, f"*column-{col.name}*"))
         section.body.extend(wrap(f"Adapters: {col.adapters}", 4))
diff --git a/doc/oil.txt b/doc/oil.txt
index 8f55186..b0b77da 100644
--- a/doc/oil.txt
+++ b/doc/oil.txt
@@ -158,12 +158,16 @@ setup({opts})                                                          *oil.setu
 --------------------------------------------------------------------------------
 COLUMNS                                                              *oil-columns*
 
+Columns can be specified as a string to use default arguments (e.g. `"icon"`),
+or as a table to pass parameters (e.g. `{"size", highlight = "Special"}`)
+
 type                                                                 *column-type*
     Adapters: *
     The type of the entry (file, directory, link, etc)
 
     Parameters:
-      {highlight} `string|fun` Highlight group
+      {highlight} `string|fun(value: string): string` Highlight group, or
+                  function that returns a highlight group
       {icons}     `table<string, string>` Mapping of entry type to icon
 
 icon                                                                 *column-icon*
@@ -171,14 +175,16 @@ icon                                                                 *column-ico
     An icon for the entry's type (requires nvim-web-devicons)
 
     Parameters:
-      {highlight} `string|fun` Highlight group
+      {highlight} `string|fun(value: string): string` Highlight group, or
+                  function that returns a highlight group
 
 size                                                                 *column-size*
     Adapters: files, ssh
     The size of the file
 
     Parameters:
-      {highlight} `string|fun` Highlight group
+      {highlight} `string|fun(value: string): string` Highlight group, or
+                  function that returns a highlight group
 
 permissions                                                   *column-permissions*
     Adapters: files, ssh
@@ -186,14 +192,16 @@ permissions                                                   *column-permission
     Access permissions of the file
 
     Parameters:
-      {highlight} `string|fun` Highlight group
+      {highlight} `string|fun(value: string): string` Highlight group, or
+                  function that returns a highlight group
 
 ctime                                                               *column-ctime*
     Adapters: files
     Change timestamp of the file
 
     Parameters:
-      {highlight} `string|fun` Highlight group
+      {highlight} `string|fun(value: string): string` Highlight group, or
+                  function that returns a highlight group
       {format}    `string` Format string (see :help strftime)
 
 mtime                                                               *column-mtime*
@@ -201,7 +209,8 @@ mtime                                                               *column-mtim
     Last modified time of the file
 
     Parameters:
-      {highlight} `string|fun` Highlight group
+      {highlight} `string|fun(value: string): string` Highlight group, or
+                  function that returns a highlight group
       {format}    `string` Format string (see :help strftime)
 
 atime                                                               *column-atime*
@@ -209,7 +218,8 @@ atime                                                               *column-atim
     Last access time of the file
 
     Parameters:
-      {highlight} `string|fun` Highlight group
+      {highlight} `string|fun(value: string): string` Highlight group, or
+                  function that returns a highlight group
       {format}    `string` Format string (see :help strftime)
 
 birthtime                                                       *column-birthtime*
@@ -217,7 +227,8 @@ birthtime                                                       *column-birthtim
     The time the file was created
 
     Parameters:
-      {highlight} `string|fun` Highlight group
+      {highlight} `string|fun(value: string): string` Highlight group, or
+                  function that returns a highlight group
       {format}    `string` Format string (see :help strftime)
 
 --------------------------------------------------------------------------------