diff --git a/.gitignore b/.gitignore
index 940794e..f9cb0ce 100644
--- a/.gitignore
+++ b/.gitignore
@@ -262,6 +262,7 @@ paket-files/
 
 # FAKE - F# Make
 .fake/
+.ionide/
 
 # JetBrains Rider
 .idea/
diff --git a/FunctionalCuid.Tests/Program.fs b/FunctionalCuid.Tests/Program.fs
index 95cdb78..be67f5e 100644
--- a/FunctionalCuid.Tests/Program.fs
+++ b/FunctionalCuid.Tests/Program.fs
@@ -15,29 +15,36 @@ module CuidTests =
       ]
   
   [<Tests>]
-  let fromStringTests =
-    testList "Cuid.fromString" [
+  let ofStringTests =
+    testList "Cuid.ofString" [
       test "fails when string is null" {
-        let x = Cuid.fromString null
+        let x = Cuid.ofString null
         Expect.isError x "Parsing should have returned an error"
         let msg = match x with Error y -> y | _ -> ""
         Expect.equal msg "string was null" "Expected error message not returned"
         }
       test "fails when string is not 25 characters" {
-        let x = Cuid.fromString "c12345566677893508"
+        let x = Cuid.ofString "c12345566677893508"
         Expect.isError x "Parsing should have returned an error"
         let msg = match x with Error y -> y | _ -> ""
         Expect.equal msg "string was not 25 characters (length 18)" "Expected error message not returned"
         }
       test "fails when string does not start with c" {
-        let x = Cuid.fromString "djld2cyuq0000t3rmniod1foy"
+        let x = Cuid.ofString "djld2cyuq0000t3rmniod1foy"
         Expect.isError x "Parsing should have returned an error"
         let msg = match x with Error y -> y | _ -> ""
         Expect.equal msg """string did not start with "c" ("djld2cyuq0000t3rmniod1foy")"""
           "Expected error message not returned"
         }
+      test "fails when string is not valid base-36" {
+        let x = Cuid.ofString "cjld2*yuq0/00t3r#niod1foy"
+        Expect.isError x "Parsing should have returned an error"
+        let msg = match x with Error y -> y | _ -> ""
+        Expect.equal msg """string was not in base-36 format ("cjld2*yuq0/00t3r#niod1foy")"""
+          "Expected error message not returned"
+        }
       test "succeeds" {
-        let x = Cuid.fromString "cjld2cyuq0000t3rmniod1foy"
+        let x = Cuid.ofString "cjld2cyuq0000t3rmniod1foy"
         Expect.isOk x "Parsing should have returned Ok"
         let cuid = match x with Ok y -> y | _ -> Cuid ""
         Expect.equal cuid (Cuid "cjld2cyuq0000t3rmniod1foy") "CUID value not correct"
@@ -53,6 +60,30 @@ module CuidTests =
         }
       ]
   
+  [<Tests>]
+  let isValidTests =
+    testList "Cuid.isValid" [
+      test "succeeds when the string is a valid CUID" {
+        Expect.isTrue ((Cuid.generateString >> Cuid.isValid) ()) "A valid CUID should have returned true"
+        }
+      test "succeeds when the string is not a valid CUID" {
+        Expect.isFalse (Cuid.isValid "abc") "An invalid CUID should have returned false"
+        }
+      ]
+  
+  [<Tests>]
+  let validationMessageTests =
+    testList "Cuid.validationMessage" [
+      test "succeeds when the string is a valid CUID" {
+        Expect.equal ((Cuid.generateString >> Cuid.validationMessage) ()) ""
+          "A valid CUID should have returned an empty validation message"
+        }
+      test "succeeds when the string is an invalid CUID" {
+        Expect.equal (Cuid.validationMessage null) "string was null"
+          "An invalid CUID should have returned its validation error message"
+        }
+      ]
+  
   [<Tests>]
   let generateStringTests =
     testList "Cuid.generateString" [
@@ -77,28 +108,34 @@ module SlugTests =
       ]
   
   [<Tests>]
-  let fromStringTests =
-    testList "Slug.fromString" [
+  let ofStringTests =
+    testList "Slug.ofString" [
       test "fails when string is null" {
-        let x = Slug.fromString null
+        let x = Slug.ofString null
         Expect.isError x "Parsing should have returned an error"
         let msg = match x with Error y -> y | _ -> ""
         Expect.equal msg "string was null" "Expected error message not returned"
         }
       test "fails when string is less than 7 characters" {
-        let x = Slug.fromString "12345"
+        let x = Slug.ofString "12345"
         Expect.isError x "Parsing should have returned an error"
         let msg = match x with Error y -> y | _ -> ""
         Expect.equal msg "string must be at least 7 characters (length 5)" "Expected error message not returned"
         }
       test "fails when string is more than 10 characters" {
-        let x = Slug.fromString "abcdefghijklmnop"
+        let x = Slug.ofString "abcdefghijklmnop"
         Expect.isError x "Parsing should have returned an error"
         let msg = match x with Error y -> y | _ -> ""
         Expect.equal msg "string must not exceed 10 characters (length 16)" "Expected error message not returned"
         }
+      test "fails when string is not valid base-36" {
+        let x = Slug.ofString "cj*q0/0#d"
+        Expect.isError x "Parsing should have returned an error"
+        let msg = match x with Error y -> y | _ -> ""
+        Expect.equal msg """string was not in base-36 format ("cj*q0/0#d")""" "Expected error message not returned"
+        }
       test "succeeds" {
-        let x = Slug.fromString "cyuq0000t"
+        let x = Slug.ofString "cyuq0000t"
         Expect.isOk x "Parsing should have returned Ok"
         let slug = match x with Ok y -> y | _ -> Slug ""
         Expect.equal slug (Slug "cyuq0000t") "Slug value not correct"
@@ -114,6 +151,30 @@ module SlugTests =
         }
       ]
   
+  [<Tests>]
+  let isValidTests =
+    testList "Slug.isValid" [
+      test "succeeds when the string is a valid Slug" {
+        Expect.isTrue ((Slug.generateString >> Slug.isValid) ()) "A valid Slug should have returned true"
+        }
+      test "succeeds when the string is not a valid Slug" {
+        Expect.isFalse (Slug.isValid "12345") "An invalid Slug should have returned false"
+        }
+      ]
+  
+  [<Tests>]
+  let validationMessageTests =
+    testList "Slug.validationMessage" [
+      test "succeeds when the string is a valid Slug" {
+        Expect.equal ((Slug.generateString >> Slug.validationMessage) ()) ""
+          "A valid Slug should have returned an empty validation message"
+        }
+      test "succeeds when the string is an invalid Slug" {
+        Expect.equal (Slug.validationMessage null) "string was null"
+          "An invalid Slug should have returned its validation error message"
+        }
+      ]
+  
   [<Tests>]
   let generateStringTests =
     testList "Slug.generateString" [
diff --git a/FunctionalCuid/FunctionalCuid.fsproj b/FunctionalCuid/FunctionalCuid.fsproj
index 2635dd1..2503630 100644
--- a/FunctionalCuid/FunctionalCuid.fsproj
+++ b/FunctionalCuid/FunctionalCuid.fsproj
@@ -2,6 +2,17 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
     <TargetFramework>netstandard2.0</TargetFramework>
+    <VersionPrefix>1.0.0</VersionPrefix>
+    <PackageReleaseNotes>Initial release</PackageReleaseNotes>
+    <Authors>danieljsummers</Authors>
+    <Company>Bit Badger Solutions</Company>
+    <PackageProjectUrl>https://github.com/danieljsummers/FunctionalCuid</PackageProjectUrl>
+    <PackageRequireLicenseAcceptance>false</PackageRequireLicenseAcceptance>
+    <RepositoryUrl>https://github.com/danieljsummers/FunctionalCuid</RepositoryUrl>
+    <RepositoryType>Git</RepositoryType>
+    <Copyright>MIT License</Copyright>
+    <PackageLicenseExpression>MIT</PackageLicenseExpression>
+    <PackageTags>Cuid Slug F-Sharp</PackageTags>
   </PropertyGroup>
   <ItemGroup>
     <Compile Include="Library.fs" />
diff --git a/FunctionalCuid/Library.fs b/FunctionalCuid/Library.fs
index ba325fe..b4dadb2 100644
--- a/FunctionalCuid/Library.fs
+++ b/FunctionalCuid/Library.fs
@@ -102,6 +102,12 @@ module private Support =
     match chars with
     | _ when chars > str.Length -> str
     | _ -> str.[str.Length - chars..]
+  
+  /// Convert a result to a boolean
+  let resultToBool x = match x with Ok _ -> true | Error _ -> false
+
+  /// Get the error message for a result with a string error message
+  let errMsg x = match x with Ok _ -> "" | Error msg -> msg
 
 
 /// Public functions for the CUID type
@@ -135,8 +141,7 @@ module Cuid =
   /// - be 25 characters long
   /// - start with "c"
   /// - be base-36 format ([0-9|a-z])
-  // TODO: extract these validations out so we can provide a "validate" function for C#/VB.NET
-  let fromString (x : string) =
+  let ofString (x : string) =
     match x with
     | null -> Error "string was null"
     | _ when x.Length <> 25 -> (sprintf "string was not 25 characters (length %i)" >> Error) x.Length
@@ -147,6 +152,14 @@ module Cuid =
   /// Get the string representation of a CUID
   let toString x = match x with Cuid y -> y
 
+  /// Is the string a valid CUID?
+  [<CompiledName "IsValid">]
+  let isValid = ofString >> resultToBool
+
+  /// Get the validation message for a CUID string
+  [<CompiledName "ValidationMessage">]
+  let validationMessage = ofString >> errMsg
+
   /// Generate a CUID as a string
   [<CompiledName "GenerateString">]
   let generateString = generate >> toString
@@ -177,8 +190,7 @@ module Slug =
   /// Create a Slug from a string
   ///
   /// The string must be between 7 and 10 characters long and base-36 format ([0-9|a-z])
-  // TODO: extract these validations out so we can provide a "validate" function for C#/VB.NET
-  let fromString (x : string) =
+  let ofString (x : string) =
     match x with
     | null -> Error "string was null"
     | _ when x.Length < 7 -> (sprintf "string must be at least 7 characters (length %i)" >> Error) x.Length
@@ -189,6 +201,14 @@ module Slug =
   /// Get the string representation of a Slug
   let toString x = match x with Slug y -> y
 
+  /// Is the string a valid Slug?
+  [<CompiledName "IsValid">]
+  let isValid = ofString >> resultToBool
+
+  /// Get the validation message for a Slug string
+  [<CompiledName "ValidationMessage">]
+  let validationMessage = ofString >> errMsg
+
   /// Generate a Slug as a string
   [<CompiledName "GenerateString">]
   let generateString = generate >> toString
diff --git a/README.md b/README.md
index 11b6e0b..1c64a28 100644
--- a/README.md
+++ b/README.md
@@ -25,23 +25,45 @@ open Cuid
 let generatedCuid = Cuid.generate ()
 
 /// Creating a CUID from a string you already know. This string must be 25
-/// characters long and start with "c".
-let cuidFromString =
-  match Cuid.fromString "cjz362bgd00005cus6t21gba0" with
+/// characters long, start with "c", and be valid base-36 (0-9 and a-z).
+let cuidOfString =
+  match Cuid.ofString "cjz362bgd00005cus6t21gba0" with
   | Error msg -> invalidOp msg
   | Ok cuid -> cuid
 
+/// Establish a valid CUID string using isValid and validationMessage instead.
+let validatedCuidString =
+  let str = "abcdefg"
+  match Cuid.isValid str with
+  | true -> str
+  | false -> (Cuid.validationMessage >> invalidOp) str
+
+/// Get the validation error for a CUID (empty string if CUID is valid).
+let cuidErrorMsg = Cuid.validationMessage "howdy"
+
 /// The string representation of a CUID
 let cuidString = Cuid.generateString ()
 ```
 
-For the `Slug` type, just replace `Cuid` with `Slug`; the validation rules for `Slug.fromString` are simply that the string has to be between 7 and 10 characters long.
+For the `Slug` type, just replace `Cuid` with `Slug`; the validation rules for `Slug.ofString` are that the string has to be between 7 and 10 base-36 characters long.
 
-For C# and VB.NET, the syntax is a bit different. Instead of `Cuid` as it reads above, it will appear as `CuidModule`; and, as `generateString` is the most likely function (method) called from those languages, its compiled name uses Pascal case. The same holds true for the `Slug` modules as well. A C# example...
+For C# and VB.NET, the syntax is a bit different. Instead of `Cuid` as it reads above, it will appear as `CuidModule`; and, as `generateString`, `isValid`, and `validationMessage` are the most likely functions (methods) called from those languages, their compiled names use Pascal case. The same holds true for the `Slug` modules as well. A C# example...
 
 ```csharp
 using Cuid;
 // ...
 var cuid = CuidModule.GenerateString();
-var slug = SlugModule.GenerateString();
+
+// example from an MVC controller
+public IActionResult Get(string cuid)
+{
+    if (CuidModule.IsValid(cuid))
+    {
+        // do something with it
+    }
+    else
+    {
+        return NotFound($"Could not find ID {cuid}; {CuidModule.ValidationMessage(cuid)}");
+    }
+}
 ```