Troubles with creating the mask

[McWorse]

An addition to my question:

I have difficulties in understanding the official explanation of creating a mask file as shown here:

https://hashcat.net/wiki/doku.php?id=mask_attack

The general format of 1 single line in the .hcmask file is as follows:

[?1,][?2,][?3,][?4,]mask

where the placeholders are as follows:

• [?1] the 1st custom charset (--custom-charset1 or -1) will be set to this value, optional
  
• [?2] the 2nd custom charset (--custom-charset2 or -2) will be set to this value, optional
  
• [?3] the 3rd custom charset (--custom-charset3 or -3) will be set to this value, optional
  
• [?4] the 4th custom charset (--custom-charset4 or -4) will be set to this value, optional
  
• [mask] the mask which should (but does not need) to use the custom-charset defined by [?1], [?2], [?3] or [?4] and can use any additional predefined charset (?l, ?u, ?d, ?h, ?H, ?s, ?a, ?b) and can contain fixed chars too (example value: pass?1?d?d?2?l?l)
  

* see the PACK program and some example hcmask files shipped by hashcat (in the masks/ folder).

Is there somewhere an example of a mask file for an own specified charset to look at?

With an example it should be easier to understand for me. Unfortunately, there are no examples for an own specified charset comming with the current hashcat version...