I heard this info from a lawyer. that's the only info I could get on-line related to it.
"Here is the official CIC policy for the visitor visas of parents. Please attach a covering letter with your visa application giving reference to this policy. Here is a link to this document on the CIC web site. http://www.cic.gc.ca/ENGLISH/resources/manuals/op/op11-eng.pdf
Excerpt from CIC Operation Manual 11: Page 9/39, Paragraph 5.13
5.13. Parents and grandparents
In April 2005, the Minister of Citizenship and Immigration made a policy decision to encourage visa officers to be more flexible in issuing temporary resident visas (TRVs), including multipleentry visas, to parents and grandparents:
• who have applications for permanent residence in process, and
• who wish to visit but do not intend to immigrate to Canada.
As per A22(2), the intent to become a permanent resident does not preclude a person from becoming a temporary resident. If a parent or grandparent intends to become a permanent resident eventually and can satisfy an officer on a balance of probabilities that they will leave Canada at the end of the authorized period of stay [as per R179], officers will normally issue a TRV (single-or multiple-entry visa). Longer validity visas should also be considered (See Procedure 16, Long-term temporary residents, below)."