README.md in prawn-swiss_qr_bill-0.4.2 vs README.md in prawn-swiss_qr_bill-0.5.0

@@ -28,11 +28,11 @@
 
 ```ruby
 require 'prawn'
 require 'prawn/swiss_qr_bill'
 
-@qr_data = {
+@bill_data = {
   creditor: {
     iban: 'CH08 3080 8004 1110 4136 9',
     address: {
       name: 'Mischa Schindowski',
       line1: 'Schybenächerweg 553',
@@ -47,25 +47,25 @@
 }
 
 Prawn::Document.generate('output.pdf', page_size: 'A4') do
   text 'A Swiss QR bill'
 
-  swiss_qr_bill(@qr_data)
+  swiss_qr_bill(@bill_data)
 end
 ```
 
 This will render the Swiss QR-bill at the bottom of the page:
 
 ![Swiss QR-bill Example, PDF](./images/sqb_example_01.png)
 
-### Options
+### Bill data structure
 
-The following options are available:
+The following data structure for the bill can be specified:
 
 ```ruby
 # *: mandatory
-@qr_data = {
+@bill_data = {
   creditor: {
     iban: '<iban>',                 # *
     address: {                      # *
       type: '<K|S>',                # default: K
       name: '<name>',               # *
@@ -94,12 +94,40 @@
 }
 ```
 
 If `debtor` or `amount` amount is not given, a box will be printed.
 
+### Options
+
+Calling `swiss_qr_bill()` method with options:
+
+```ruby
+# ...
+Prawn::Document.generate('output.pdf', page_size: 'A4') do
+  # ...
+
+  # raises InvalidIBANError when @bill_data[:creditor][:iban] is invalid
+  swiss_qr_bill(@bill_data, validate: true)
+end
+```
+
+Available options:
+
+| Option | Data type | Description | Default |
+| --- | --- | --- | --- |
+| `validate` | boolean | Validates IBAN and Reference Number and raises several errors | `false` |
+
+Errors which can be raised during validation:
+
+* `MissingIBANError`: When IBAN is missing.
+* `InvalidIBANError`: When IBAN is invalid. It checks for CH-IBAN only.
+* `InvalidReferenceError`: When reference is invalid. It checks for a valid QRR or SCOR reference
+
 ## Important
 
-This library does not validate (yet) IBAN, reference or the given QR data.
+This library can validate IBAN (switzerland only) and reference number (types QRR and SCOR).
+It does not however validate, if the given data is fully valid according to the implementation guidelines.
+
 Please refer to the implementation guidelines and the Swiss QR-bill validaton
 portal by SIX below.
 
 ## Contributing