add info about accessibility modifiers in constructors for F# records (#49028)

* add info for constructor accessibility modifiers

* make changes from feedback

* remove unnecessary semicolon

* minor fixes

* Update docs/fsharp/language-reference/records.md

---------

Co-authored-by: Bill Wagner <[email protected]>

Author: StuartMosquera

docs/fsharp/language-reference/records.md

@@ -6,19 +6,23 @@ ms.date: 12/21/2021
 ---
 # Records (F#)
 
-Records represent simple aggregates of named values, optionally with members. They can either be structs or reference types.  They are reference types by default.
+Records represent simple aggregates of named values, optionally with members. They can either be structs or reference types. They are reference types by default.
 
 ## Syntax
 
 ```fsharp
 [ attributes ]
 type [accessibility-modifier] typename =
-    { [ mutable ] label1 : type1;
-      [ mutable ] label2 : type2;
-      ... }
+    [accessibility-modifier] { 
+        [ mutable ] label1 : type1;
+        [ mutable ] label2 : type2;
+        ... 
+    }
     [ member-list ]
 ```
 
+The `accessibility modifier` before the `typename` affects the visibility of the entire type, and is `public` by default. The second `accessibility modifier` only affects the constructor and fields.
+
 ## Remarks
 
 In the previous syntax, *typename* is the name of the record type, *label1* and *label2* are names of values, referred to as *labels*, and *type1* and *type2* are the types of these values. *member-list* is the optional list of members for the type.  You can use the `[<Struct>]` attribute to create a struct record rather than a record which is a reference type.
@@ -96,33 +100,33 @@ For example, the following code defines a `Person` and `Address` type as mutuall
 ```fsharp
 // Create a Person type and use the Address type that is not defined
 type Person =
-  { Name: string
-    Age: int
-    Address: Address }
+    { Name: string
+      Age: int
+      Address: Address }
 // Define the Address type which is used in the Person record
 and Address =
-  { Line1: string
-    Line2: string
-    PostCode: string
-    Occupant: Person }
+    { Line1: string
+      Line2: string
+      PostCode: string
+      Occupant: Person }
 ```
 
 To create instances of both, you do the following:
 
 ```fsharp
 // Create a Person type and use the Address type that is not defined
 let rec person =
-  {
-      Name = "Person name"
-      Age = 12
-      Address =
-          {
-              Line1 = "line 1"
-              Line2 = "line 2"
-              PostCode = "abc123"
-              Occupant = person
-          }
-  }
+    {
+        Name = "Person name"
+        Age = 12
+        Address =
+            {
+                Line1 = "line 1"
+                Line2 = "line 2"
+                PostCode = "abc123"
+                Occupant = person
+            }
+    }
 ```
 
 If you were to define the previous example without the `and` keyword, then it would not compile. The `and` keyword is required for mutually recursive definitions.
@@ -147,9 +151,9 @@ You can specify members on records much like you can with classes. There is no s
 
 ```fsharp
 type Person =
-  { Name: string
-    Age: int
-    Address: string }
+    { Name: string
+      Age: int
+      Address: string }
 
     static member Default =
         { Name = "Phillip"
@@ -163,9 +167,9 @@ If you use a self identifier, that identifier refers to the instance of the reco
 
 ```fsharp
 type Person =
-  { Name: string
-    Age: int
-    Address: string }
+    { Name: string
+      Age: int
+      Address: string }
 
     member this.WeirdToString() =
         this.Name + this.Address + string this.Age
@@ -174,6 +178,48 @@ let p = { Name = "a"; Age = 12; Address = "abc123" }
 let weirdString = p.WeirdToString()
 ```
 
+## Accessibility Modifiers on Records
+
+The following code illustrates the use of accessibility modifiers. There are three files in the project: `Module1.fs`, `Test1.fs`, and `Test2.fs`. An internal record type and a record type with a private constructor are defined in Module1.
+
+```fsharp
+// Module1.fs
+
+module Module1
+
+type internal internalRecd = { X: int }
+
+type recdWithInternalCtor = private { Y: int }
+```
+
+In the `Test1.fs` file, the internal record must be initialized with the `internal` access modifier, that's because the protection level of the value and the record must match, and both must belong to the same assembly.
+
+```fsharp
+// Test1.fs
+
+module Test1
+
+open Module1
+
+let myInternalRecd1 = { X = 2 } // This line will cause a compiler error.
+
+let internal myInternalRecd2 = { X = 4 } // This is OK
+```
+
+In the `Test2.fs` file, the record with the private constructor cannot be initialized directly due the protection level of the constructor.
+
+```fsharp
+// Test2.fs
+
+module Test2
+
+open Module1
+
+let myRecdWithInternalCtor = { Y = 6 } // This line will cause a compiler error.
+```
+
+For more information about accessibility modifiers, see the [Access Control](./access-control.md) article.
+
 ## Differences Between Records and Classes
 
 Record fields differ from class fields in that they are automatically exposed as properties, and they are used in the creation and copying of records. Record construction also differs from class construction. In a record type, you cannot define a constructor. Instead, the construction syntax described in this topic applies. Classes have no direct relationship between constructor parameters, fields, and properties.