Key

Description: The key property can be defined in the option Object.

Edit
ctr('.test', {
width: 200px
element: {
option: {
key: 'after'
}
content: 'ctr'
font-size: 1em
}
})
.test:
width: 200px
element:
option:
key: after
content: ctr
font-size: 1em
.test {
width: 200px;
}
.test::after {
font-size: 1em;
content: "ctr";
}
ctr('.test', {
  width: 200px
  element: {
    option: {
      key: 'after'
    }
    content: 'ctr'
    font-size: 1em
  }
})
.test {
  width: 200px;
}
.test::after {
  font-size: 1em;
  content: "ctr";
}
.test:
  width: 200px
  element:
    option:
      key: after
    content: ctr
    font-size: 1em

Colon

Description: The number of colons can be altered through the colon option property.

Edit
ctr('.test', {
width: 200px
before: {
option: {
colon: ':'
}
content: 'beer'
}
after: {
option: {
colon: ':::::::::::::::::'
}
content: 'whiskey'
}
})
.test:
width: 200px
before:
option:
colon: ':'
content: beer
after:
option:
colon: ':::::::::::::::::'
content: whiskey
.test {
width: 200px;
}
.test:before {
content: "beer";
}
.test:::::::::::::::::after {
content: "whiskey";
}
ctr('.test', {
  width: 200px
  before: {
    option: {
      colon: ':'
    }
    content: 'beer'
  }
  after: {
    option: {
      colon: ':::::::::::::::::'
    }
    content: 'whiskey'
  }
})
.test {
  width: 200px;
}
.test:before {
  content: "beer";
}
.test:::::::::::::::::after {
  content: "whiskey";
}
.test:
  width: 200px
  before:
    option:
      colon: ':'
    content: beer
  after:
    option:
      colon: ':::::::::::::::::'
    content: whiskey

Notes

Stringify

Description: The value of false for the stringify option property ensures the content value is not converted into a String.

Edit
ctr('.test', {
width: 200px
counter-increment: linenumber
before: {
option: {
stringify: false
}
content: counter(linenumber)
}
})
.test:
width: 200px
counter-increment: linenumber
before:
option:
stringify: false
content: counter(linenumber)
.test {
width: 200px;
counter-increment: linenumber;
}
.test::before {
content: counter(linenumber);
}
ctr('.test', {
  width: 200px
  counter-increment: linenumber
  before: {
    option: {
      stringify: false
    }
    content: counter(linenumber)
  }
})
.test {
  width: 200px;
  counter-increment: linenumber;
}
.test::before {
  content: counter(linenumber);
}
.test:
  width: 200px
  counter-increment: linenumber
  before:
    option:
      stringify: false
    content: counter(linenumber)

Notes

Content False

Description: The value of false for the content property is equivalent to "".

Edit
ctr('.test', {
width: 200px
before: {
content: false
}
})
.test:
width: 200px
before:
content: false
.test {
width: 200px;
}
.test::before {
content: "";
}
ctr('.test', {
  width: 200px
  before: {
    content: false
  }
})
.test {
  width: 200px;
}
.test::before {
  content: "";
}
.test:
  width: 200px
  before:
    content: false