Explanation of the instructions for Line 4 of Schedule SE

Question

I'm trying to fill out Schedule SE for 2016. I'm confused by line 4, which includes the phrase

don't file this schedule unless you have an amount on line 1b.

where Line 1b is:

If you received social security retirement or disability benefits, enter the amount of Conservation Reserve Program payments included on Schedule F, line 4b, or listed on Schedule K-1 (Form 1065), box 20, code Z

Line 1b doesn't apply to me, yet I'm pretty sure that I do have to file Schedule SE. Should I just ignore this comment?

P.S. The instructions seem to refer to the "total of lines 1a and 2", which is basically what is on line 3 (given that line 1b doesn't apply to me). So I suspect that there is a typo on Schedule SE and that "line 1b" in the cited phrase should actually be "line 3"; could this be?

Answer 1

It needs to be taken in the context of the first part of the sentence:

If less than $400, you don't owe self-employment tax; don't file this schedule unless you have an amount on line 1b

So I interpret it as: if your taxable self-employment income (Line 3 * 92.35%) is less than $400, you don't need to pay self-employment tax (and hence don't need to fill out the form) unless you have an amount on line 1b.