Can you tell me where you found this information? All I have found is the following which would tend to rule out parcel post.

TF

Taken from the USPS web site

Size Limits - Parcel Post
The following size limits apply to rectangular parcel post packages sent to most destination countries:

Minimum length and width: 5-1/2 inches by 3-1/2 inches
Maximum length: 42 inches
Maximum length + girth combined: 79 inches

Some countries have larger size limits. Consult your local Post Office facility for the size limits that apply to the country to which you are mailing.