Pre-OCS Laundry Marking and Running Shoe Lacing

I have a few questions about preparing gear before reporting to OCS:

Laundry Marking:

• Can I mark my clothing items before arriving, or should I wait until OCS?
• Is there an official regulation specifying how and where to mark items (shirts, pants, socks, compression shorts, towels)?
• At basic training, I used first initial of last name + last four of SSN. Does OCS use the same system?
• The candidate regulations mention marking laundry bags with "last name and ZAP #" but don't specify placement. What is a ZAP number, and where should this marking go?

Footwear:

• Should running shoes be laced left-over-right like boots, or does that only apply to boots?

Any insight from recent graduates or current candidates would be appreciated. Thanks in advance.