Acknowledgement or Jurat?
Acknowledgement
An acknowledgement is one of the most common types of notarial acts. According to Colorado notary law (CRS 12-55-205), in executing an acknowledgemt, the notary certifies that:
The signer personally appeared before the notary
The signer was positively identified by the notary
The signer acknowledged to the notary that the signature was freely made for the purposes stated in the document
Jurat
A jurat, according to Colorado law, is a 'written affirmation' (CRS 12-55-119). In executing a jurat, a notary certifies:
The signer personally appeared before the notary at the time of the notarization.
The signer was positively identified
The notary witnessed the signature at the time of the notarization
An oath or affirmation was administered (i.e. 'Do you solemnly swear ...'?)
A jurat requires the signer to take an oath from the notary. An acknowledgement does not require that the signer take an oath.
I often get requests from people who need a document 'notarized'. In many cases it's a hand-written or typed letter that does not contain a notary certificate (notary wording) on it. In cases like this, the signer will have to tell me what type of notarization to perform. It isn't as simple as taking out a notary stamp and stamping it.
And I may not choose what type of notarization to perform. That is considered unauthorized practice of law. So it is up to the signer to tell the notary what type of notarization to perform.
There are a couple of ways that a notary certificate can be added to a document that does not already contain notary wording. Below are examples of an acknowledgement:
If there is enough room on the document, an acknowledgement stamp with the appropriate wording can be added to it. 
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| If there is not enough room for a stamp, a loose certificate can be attached (stapled) to the document. |  |
This is the wording for a jurat, according to Colorado law (CRS 12-55-110: ____________________________________________________________ State of Colorado
County of ________ Subscribed and sworn (or affirmed) before me in the county of _______, state of Colorado, this _____________ day of ____________________, 20__. |
 If there is enough room on a document requiring a jurat, I can stamp the certificate onto the document. |  |
 | Jurat With Affiant Statement This is a sample of a Jurat that can be attached to a document. Like the stamp impression above, it can be used when the document does not contain a notary certificate, or if there isn't enough room on the document to place a jurat stamp. The difference is that it provides a space for the signer to make their own statement. |
CRS 12-55-205. Certificate of person taking acknowledgement
(1) The person taking an acknowledgement shall certify that:
(a) The person acknowledging appeared before him and acknowledged he executed the instrument; and
(b) The person acknowledging was known to the person taking the acknowledgement or that the person taking the acknowledgement had satisfactory evidence that the person acknowledging was the person described in and who executed the instrument. |