diff --git a/README.md b/README.md
index d58dc6a..f655c53 100644
--- a/README.md
+++ b/README.md
@@ -1,222 +1,248 @@
 # Summary
+
 This program generates **fully customizable random passwords**, with almost **any desired pattern or length**, using the same syntax as [Regular Expressions](https://www.regular-expressions.info/quickstart.html) for **character classes** (POSIX-style), **repetition** (`{N}` or `{M,N}`) and **capturing groups** (`(...)`).
 
 See [examples](#examples) for clarity.
 
 # Build and install
+
 Run:
+
 ```sh
 go get github.com/ilius/repassgen
 ```
+
 This will compile and then copy `repassgen` executable file to `$GOPATH/bin/` directory.
 
 If you just want to compile without installing it
+
 ```sh
 go get -d github.com/ilius/repassgen
 cd $GOPATH/src/github.com/ilius/repassgen
 go build
 ```
-Then `repassgen` binary file will be created in current directory.
 
+Then `repassgen` binary file will be created in current directory.
 
 # Features of regexp
-- [x] Simple repetition: `{N}`
-- [x] Range repetition: `{M,N}`
-- [x] Manual character range, like `[a-z1-579]`
-- [x] Repeatable groups with `(...){N}`, like  `([a-z]{2}[1-9]){3}`
-- [x] `[:alnum:]` Alphanumeric characters
-- [x] `[:alpha:]` Alphabetic characters
-- [x] `[:word:]` Word characters (letters, numbers and underscores)
-- [x] `[:upper:]` Uppercase letters
-- [x] `[:lower:]` Lowercase letters
-- [x] `[:graph:]` Visible characters
-- [x] `[:print:]` Visible characters and spaces (anything except control characters)
-- [x] `[:digit:]` Digits
-- [x] `[:xdigit:]` Hexadecimal digits
-- [x] `[:punct:]` Punctuation (and symbols).
-- [x] `[:space:]` All whitespace characters, including line breaks
-- [x] `[:blank:]` Space and tab
-- [x] `[:cntrl:]` Control characters
-- [x] `[:ascii:]` ASCII characters
-- [x] [Unicode code points](https://www.regular-expressions.info/unicode.html), like `[\u00e0-\u00ef]{5}`
-- [x] Group references `\1`, `\2`, etc
-- [x] `\d` Digits
-- [x] `\w` Word characters: alphanumeric and underline, same as `[a-zA-Z0-9_]`
-
 
+- \[x\] Simple repetition: `{N}`
+- \[x\] Range repetition: `{M,N}`
+- \[x\] Manual character range, like `[a-z1-579]`
+- \[x\] Repeatable groups with `(...){N}`, like  `([a-z]{2}[1-9]){3}`
+- \[x\] `[:alnum:]` Alphanumeric characters
+- \[x\] `[:alpha:]` Alphabetic characters
+- \[x\] `[:word:]` Word characters (letters, numbers and underscores)
+- \[x\] `[:upper:]` Uppercase letters
+- \[x\] `[:lower:]` Lowercase letters
+- \[x\] `[:graph:]` Visible characters
+- \[x\] `[:print:]` Visible characters and spaces (anything except control characters)
+- \[x\] `[:digit:]` Digits
+- \[x\] `[:xdigit:]` Hexadecimal digits
+- \[x\] `[:punct:]` Punctuation (and symbols).
+- \[x\] `[:space:]` All whitespace characters, including line breaks
+- \[x\] `[:blank:]` Space and tab
+- \[x\] `[:cntrl:]` Control characters
+- \[x\] `[:ascii:]` ASCII characters
+- \[x\] [Unicode code points](https://www.regular-expressions.info/unicode.html), like `[\u00e0-\u00ef]{5}`
+- \[x\] Group references `\1`, `\2`, etc
+- \[x\] `\d` Digits
+- \[x\] `\w` Word characters: alphanumeric and underline, same as `[a-zA-Z0-9_]`
 
 # Aditional Features (not part of regexp)
-- [x] Combined multiple named/manual character classes, for example:
-    * `[:digit:a-m]`
-    * `[:digit::alpha:]` = `[:alnum:]`
-- [x] `[:b32:]` Crockford's Base32 alphabet (lowercase)
-- [x] `[:B32:]` Crockford's Base32 alphabet (uppercase)
-- [x] `[:B32STD:]` Standard Base32 alphabet (uppercase)
-- [x] `[:b64:]` Standard Base64 alphabet
-- [x] `[:b64url:]` URL-safe Base64 alphabet
-- [x] `$base64(...)` Base64 encode function (input is hex-encoded)
-- [x] `$base64url(...)` URL-safe Base64 encode function (input is hex-encoded)
-- [x] `$base32(...)` Crockford's Base32 encode function (lowercase) (input is hex-encoded)
-- [x] `$BASE32(...)` Crockford's Base32 encode function (uppercase) (input is hex-encoded)
-- [x] `$base32std(...)` Standard Base32 encode function (uppercase, with no padding) (input is hex-encoded)
-- [x] `$hex(...)` Hex encode function (lowercase)
-- [x] `$HEX(...)` Hex encode function (uppercase)
-- [x] Show [entropy](https://en.wikipedia.org/wiki/Password_strength#Entropy_as_a_measure_of_password_strength) of pattern
-    * Use `repassgen -entropy 'PATTERN'` command
-    * Indicates strength of generated passwords, the higher the better
-    * We recommand at least 47 bits (equal to 8 alphanumeric: `[:alnum:]{8}`)
-    * Entropy of pattern is more important than entropy of password, if you re-use patterns
-- [x] `$hex2dec(...)` Convert hexadecimal number to decimal number
-- [x] `$escape(...)` Escape unicode characters, non-printable characters and double quote
-- [x] `$?(...)` Randomly include or omit the string/pattern (%50 chance, adds 1 bit to entropy)
-- [x] `$bip39word(N)` Generate N words from BIP-39 English mnemonic words
-- [x] `$bip39encode(...)` Encode hex-encoded bytes into some BIP-39 English mnemonic words
-- [x] `$date(2000,2020,-)` Generate a random date in the given year range
-- [x] `$space(...)` Adds spaces between each two characters of string (generated from given pattern)
-- [x] `$expand(|...)` Adds `|` (for example) between each two characters (similar to `$space`)
-- [x] `$rjust(PATTERN,N,X)` Justify to right, `N` is width (N>=1), `X` is the character to fill
-- [x] `$ljust(PATTERN,N,X)` Justify to left, similar to `$rjust`
-- [x] `$center(PATTERN,N,X)` Justify to center, similar to `$rjust`
-- [x] `$pyhex(...)` Convert hex-encoded bytes to Python `bytes` with hex values (like `b'\x74\x65\x73\x74'`)
-- [x] `$romaji(...)` Converts Japanese hiragana/katakana string to Latin
-
 
+- \[x\] Combined multiple named/manual character classes, for example:
+  - `[:digit:a-m]`
+  - `[:digit::alpha:]` = `[:alnum:]`
+- \[x\] `[:b32:]` Crockford's Base32 alphabet (lowercase)
+- \[x\] `[:B32:]` Crockford's Base32 alphabet (uppercase)
+- \[x\] `[:B32STD:]` Standard Base32 alphabet (uppercase)
+- \[x\] `[:b64:]` Standard Base64 alphabet
+- \[x\] `[:b64url:]` URL-safe Base64 alphabet
+- \[x\] `$base64(...)` Base64 encode function (input is hex-encoded)
+- \[x\] `$base64url(...)` URL-safe Base64 encode function (input is hex-encoded)
+- \[x\] `$base32(...)` Crockford's Base32 encode function (lowercase) (input is hex-encoded)
+- \[x\] `$BASE32(...)` Crockford's Base32 encode function (uppercase) (input is hex-encoded)
+- \[x\] `$base32std(...)` Standard Base32 encode function (uppercase, with no padding) (input is hex-encoded)
+- \[x\] `$hex(...)` Hex encode function (lowercase)
+- \[x\] `$HEX(...)` Hex encode function (uppercase)
+- \[x\] Show [entropy](https://en.wikipedia.org/wiki/Password_strength#Entropy_as_a_measure_of_password_strength) of pattern
+  - Use `repassgen -entropy 'PATTERN'` command
+  - Indicates strength of generated passwords, the higher the better
+  - We recommand at least 47 bits (equal to 8 alphanumeric: `[:alnum:]{8}`)
+  - Entropy of pattern is more important than entropy of password, if you re-use patterns
+- \[x\] `$hex2dec(...)` Convert hexadecimal number to decimal number
+- \[x\] `$escape(...)` Escape unicode characters, non-printable characters and double quote
+- \[x\] `$?(...)` Randomly include or omit the string/pattern (%50 chance, adds 1 bit to entropy)
+- \[x\] `$bip39word(N)` Generate N words from BIP-39 English mnemonic words
+- \[x\] `$bip39encode(...)` Encode hex-encoded bytes into some BIP-39 English mnemonic words
+- \[x\] `$date(2000,2020,-)` Generate a random date in the given year range
+- \[x\] `$space(...)` Adds spaces between each two characters of string (generated from given pattern)
+- \[x\] `$expand(|...)` Adds `|` (for example) between each two characters (similar to `$space`)
+- \[x\] `$rjust(PATTERN,N,X)` Justify to right, `N` is width (N>=1), `X` is the character to fill
+- \[x\] `$ljust(PATTERN,N,X)` Justify to left, similar to `$rjust`
+- \[x\] `$center(PATTERN,N,X)` Justify to center, similar to `$rjust`
+- \[x\] `$pyhex(...)` Convert hex-encoded bytes to Python `bytes` with hex values (like `b'\x74\x65\x73\x74'`)
+- \[x\] `$romaji(...)` Converts Japanese hiragana/katakana string to Latin
 
 # Examples
+
 - Alphanumeric password with length 12
-    ```sh
-    $ repassgen '[:alnum:]{12}'
-    q8nrqhPQFNqj
-    ```
+
+  ```sh
+  $ repassgen '[:alnum:]{12}'
+  q8nrqhPQFNqj
+  ```
 
 - Alphabetic password with length 12
-    ```sh
-    $ repassgen '[:alpha:]{12}'
-    wiADcFkhpjsk
-    ```
+
+  ```sh
+  $ repassgen '[:alpha:]{12}'
+  wiADcFkhpjsk
+  ```
 
 - Lowercase alphabetic password with length 16
-    ```sh
-    $ repassgen '[:lower:]{16}'
-    rnposblbuduotibe
-    ```
+
+  ```sh
+  $ repassgen '[:lower:]{16}'
+  rnposblbuduotibe
+  ```
 
 - Uppercase alphabetic password with length 16
-    ```sh
-    $ repassgen '[:upper:]{16}'
-    TQZZJHKQRKETOFNZ
-    ```
+
+  ```sh
+  $ repassgen '[:upper:]{16}'
+  TQZZJHKQRKETOFNZ
+  ```
 
 - Numeric password with length 8
-    ```sh
-    $ repassgen '[:digit:]{8}'
-    47036294
-    ```
+
+  ```sh
+  $ repassgen '[:digit:]{8}'
+  47036294
+  ```
 
 - A custom combination: 7 uppercase, space, 7 lowercase, space, 2 digits
-    ```sh
-    $ repassgen '[:upper:]{7} [:lower:]{7} [:digit:]{2}'
-    UOHMGVM toubgvs 73
-    ```
+
+  ```sh
+  $ repassgen '[:upper:]{7} [:lower:]{7} [:digit:]{2}'
+  UOHMGVM toubgvs 73
+  ```
 
 - Password with length 12, using only Base64 characters
-    ```sh
-    $ repassgen '[:b64:]{12}'
-    6+BA71WCy90I
-    ```
+
+  ```sh
+  $ repassgen '[:b64:]{12}'
+  6+BA71WCy90I
+  ```
 
 - Password with length 12, using only URL-safe Base64 characters
-    ```sh
-    $ repassgen '[:b64url:]{12}'
-    j15w_qTncikR
-    ```
+
+  ```sh
+  $ repassgen '[:b64url:]{12}'
+  j15w_qTncikR
+  ```
 
 - Password with length 16, using only Crockford's Base32 characters (lowercase)
-    ```sh
-    $ repassgen '[:b32:]{16}'
-    zmt87n9hpcd2w28h
-    ```
+
+  ```sh
+  $ repassgen '[:b32:]{16}'
+  zmt87n9hpcd2w28h
+  ```
 
 - Password with length 16, using only Crockford's Base32 characters (uppercase)
-    ```sh
-    $ repassgen '[:B32:]{16}'
-    HJ48VSR4Y0DHQ9EV
-    ```
+
+  ```sh
+  $ repassgen '[:B32:]{16}'
+  HJ48VSR4Y0DHQ9EV
+  ```
 
 - Password with length 16, using Crockford's Base32 characters and punctuations
-    ```sh
-    $ repassgen '[:b32::punct:]{16}'
-    20s:z.5mbwws474y
-    ```
+
+  ```sh
+  $ repassgen '[:b32::punct:]{16}'
+  20s:z.5mbwws474y
+  ```
 
 - Specify character range manually: lowercase alphebetic with length 16
-    ```sh
-    $ repassgen '[a-z]{16}'
-    qefqiocrabpiaags
-    ```
+
+  ```sh
+  $ repassgen '[a-z]{16}'
+  qefqiocrabpiaags
+  ```
 
 - Specify character range manually: alphanumeric with length 12
-    ```sh
-    $ repassgen '[a-zA-Z0-9]{12}'
-    XcwDAagzMlwv
-    ```
+
+  ```sh
+  $ repassgen '[a-zA-Z0-9]{12}'
+  XcwDAagzMlwv
+  ```
 
 - Include non-random characters in the password (here: Test / , .)
-    ```sh
-    $ repassgen 'Test-[:alpha:]{4}/[:alpha:]{4},[:alpha:]{4}.[:alpha:]{4}'
-    Test-Jcis/uLwq,SazR.CEFJ
-    ```
+
+  ```sh
+  $ repassgen 'Test-[:alpha:]{4}/[:alpha:]{4},[:alpha:]{4}.[:alpha:]{4}'
+  Test-Jcis/uLwq,SazR.CEFJ
+  ```
 
 - A 16-digit number similar to a credit card number
-    ```sh
-    repassgen '[:digit:]{4}-[:digit:]{4}-[:digit:]{4}-[:digit:]{4}'
-    3996-9634-1459-0656
-    ```
+
+  ```sh
+  repassgen '[:digit:]{4}-[:digit:]{4}-[:digit:]{4}-[:digit:]{4}'
+  3996-9634-1459-0656
+  ```
 
 - Alphabetic password with a length between 12 and 16 characters
-    ```sh
-    $ repassgen '[:alpha:]{12,16}'
-    uamePKmuUUUcI
-    ```
+
+  ```sh
+  $ repassgen '[:alpha:]{12,16}'
+  uamePKmuUUUcI
+  ```
 
 - Gerenate random bytes, then run Base64 encode function
-    ```sh
-    $ repassgen '$base64($byte(){12})'
-    bsOuN8KuRsOFw5jClkDDjMOrFA==
-    ```
+
+  ```sh
+  $ repassgen '$base64($byte(){12})'
+  bsOuN8KuRsOFw5jClkDDjMOrFA==
+  ```
 
 - Gerenate random bytes, then run Crockford's Base32 encode function
-    ```sh
-    $ repassgen '$base32($byte(){12})'
-    c51e2kk1aafe3jngm3gxqrazpwqva
-    ```
+
+  ```sh
+  $ repassgen '$base32($byte(){12})'
+  c51e2kk1aafe3jngm3gxqrazpwqva
+  ```
 
 - Use `-` or `[` or `]` inside `[...]`
-    ```sh
-    $ repassgen '[.\- ]{50}'
-    - .-.-- --.------- --.. -.---.-.. -- --..-..  .---
-    ```
 
-    ```sh
-    $ repassgen '[a-z\[\]\-]{20}'
-    nylhjcdq-qcaajvpcxuo
-    ```
+  ```sh
+  $ repassgen '[.\- ]{50}'
+  - .-.-- --.------- --.. -.---.-.. -- --..-..  .---
+  ```
+
+  ```sh
+  $ repassgen '[a-z\[\]\-]{20}'
+  nylhjcdq-qcaajvpcxuo
+  ```
 
 - Use whitespace characters like newline or tab (inside or outside `[...]`)
-    ```sh
-    $ repassgen '[a-z\t]{5}\t[a-z\t]{5}\n[a-z\t]{10}'
-    caelk	zccqm
-    zpbgjba	pm
-    ```
+
+  ```sh
+  $ repassgen '[a-z\t]{5}\t[a-z\t]{5}\n[a-z\t]{10}'
+  caelk	zccqm
+  zpbgjba	pm
+  ```
 
 - Generate 12 random mnemonic words from [BIP-39](https://en.bitcoin.it/wiki/BIP_0039) English words
-    ```sh
-    $ repassgen '$bip39word(12)'
-    bachelor run match video bitter nuclear hungry gossip spoon lottery grab cabbage
-    ```
+
+  ```sh
+  $ repassgen '$bip39word(12)'
+  cinnamon purity funny pigeon arrive equal foil alter life accident bar roast
+  ```
 
 - Generate 16 random bytes, then encode it to [BIP-39](https://en.bitcoin.it/wiki/BIP_0039) English mnemonic words
-    ```sh
-    $ repassgen '$bip39encode($byte(){16})'
-    hybrid grow tide eight blouse cost math secret fire pair throw circle praise tonight bid senior injury glide tide denial account
-    ```
+
+  ```sh
+  $ repassgen '$bip39encode($byte(){16})'
+  useful come fall plunge breeze side skill another boil expose essence about
+  ```