A symbol is created when newLISP first sees it, when calling the load, sym, or eval-string functions. When newLISP reads a source file, symbols are created before evaluation occurs.
In manual contexts chapter, I see above words. Is it a typo?
when calling the load, sym ... should be 'while calling the ...' ?
We use when, not while, to talk about something that occurs at the same time as a longer action or event that is described in the main clause:
* I was asleep in my chair when Dora rang to say she wasn't coming home.
* We were playing monopoly when the lights went off.
We also use when, not while, to talk about one event that happens immediately after another and to talk about periods of time in the past.
* When the lights went out, everybody groaned: "Oh no, not another power cut!"
* When I was a little boy, power cuts were very frequent, but that was just after the war.
When can also be used instead of whenever, meaning every time that:
* I always visit my mother-in-law when I'm in Manchester.
* I always visit my mother-in-law whenever I'm in Manchester.
-- xytroxon
"Many computers can print only capital letters, so we shall not use lowercase letters."
-- Let's Talk Lisp (c) 1976
Actually, you quoted the wrong section from this article. The relevant section is the "when or while" section, not the "when not while" section.
when or while
We use both when and while as subordinating conjunctions to introduce adverbial clauses of time. They mean during the time that and indicate that something is or was happening when something else occurred:
The prisoners escaped when / while the prison warders were eating their lunch.
When / While the prison warders were eating their lunch, the prisoners escaped.
Hence, in the case reference by csfreebird, either "when" or "while" can be used.