居士, how do you understand this

Below is the extract from I-131 Instruction:

If you are in the United States and wish to travel
abroad, you do not need to apply for advance parole if both conditions described below in numbers 1 and 2 are met:
1. You are in one of the following nonimmigrant categories:
a. An H-1, temporary worker, or H-4, spouse or child of
an H-1; or
b. An L-1, intracompany transferee, or L-2, spouse or
child of an L-1; or
c. A K-3, spouse, or K-4, child, of a U.S. citizen; or
d. A V-2, spouse, or V-3, child, of a lawful permanent
resident; and

2. A Form I-485, Application to Register Permanent
Residence or Adjust Status, was filed on your behalf and is pending with the CIS.

However, upon returning to the United States, you must
present your valid H, L, K or V nonimmigrant visa and
continue to remain eligible for that status.

Thank you!