Second job with non-sponsor

i am in tier 2 general for an year now, one of my friend's employer has got vacancy for a weekend job 16hours only.
i know as per UKBA i dont need to inform if it is upto 20hours.
but this job is not the same as my current job.

can i work even if the job does not fall under SOC codes ?? and
do i need to inform UKBA if i take the job???

If the job is not in the same sector and at the same level, you may have to apply for a seperate Tier 2. Check Tier 2 guidance for more details. FYI, I've copied a sub-text from the guidance doc:

"
209. You do not need to inform us of any supplementary employment, as long as it is:
• in either a job on the Shortage Occupation List or a job in the same sector and at the same professional level as the work for which your Certificate of Sponsorship was assigned; and
• no more than 20 hours per week; and
• outside of the normal working hours for which your Certificate of Sponsorship was assigned.

210. In addition, you must continue to work for your sponsor in the job recorded on your Certificate of Sponsorship.
"