Graphical symbol for Normally Open Held Closed limit switch

[patm72]

I'm currently trying to hold my ground over the symbolic representation of a Normally Closed Held Open switch with an engineer. He pretends my representation is not per ISA 5.1. As far as I can see from the internet, I do not see a representation of such a switch at all according to this standard... unless I'm missing something.

I found lots of examples suggesting I'm right with the way I represent it, but he keeps on refuting that.

So I'm asking here if somebody would be kind enough to share with me the correct way of representing a NCHO switch, and per which set of standard.

Note: the engineer is a consulting engineer, in a different location, and won't share with me his standard document, he is only refering to "ISA 5.1".

Thanks.

 

[danw2]

Here is a partial page from ISA 5.1 2009 with electrical symbols. It does not illustrate the held closed/open versions.
Items 10 through 15 are actuation symbols: rotary (manual), pressure, Differential pressure, liquid level, temperature, flow.

And here is a 'motor controls' graphic showing the same symbols and the corresponding held open/closed versions:

 

[patm72]

Thank you Danw2.
I had already seen this and provided similar links to that engineer, to no avail. The way the NCHO is represented is how I did it, but that person wants it as a NC contact, the way they are asking, but they call it NCHO. Go figure... In RED in the attached, you can sse his comments.