This is a continuation of a long topic, addressed by post number rather than by page. Start at post 1 · go to the accepted answer.
Fine by me. I had wanted a stronger conclusion and there is not one available.
Where the same certificate image appears with different lot numbers, that is a documentation finding worth reporting with the images attached.
I read post #30 twice before replying, because I had assumed the opposite.
My experience of documentation contradicts the reply above. I am posting it as a data point rather than as a refutation, because one person's experience is exactly that.
Unresponsiveness: a supplier that does not reply to reasonable requests for documentation or clarification is showing you something about how they operate.
Answering the documentation question as asked, then the question I think is meant. As asked: yes, with the qualification below. As meant: it depends on how the first measurement was taken.
Post #36 is right about the mechanism and I think understates the practical bit.
The question underneath documentation is usually "how would I tell?" rather than "what is true?", and that one has a method attached to it.
Write down what you would expect to see under each hypothesis before you collect anything. If they predict the same observation, collecting it will not help.
Coming back to post #34, because the follow-up matters more than the original answer.
A stock listing that never changes and a lead time that never varies are both worth noticing. Real operations have variation in them.
If it helps: the failure mode here is usually boring rather than dramatic.
Same experience here, different supplier, so it is at least not unique to one of them.
Coming back to post #39, because the follow-up matters more than the original answer.
Counterpoint on documentation, offered without confidence: the same observation is consistent with a much duller explanation, and nobody has ruled the dull one out.
Post #39 is right about the mechanism and I think understates the practical bit.
Prices well below the rest of the market are a fact rather than a finding. They are worth noting and they do not establish anything on their own.
Nothing above should be read as advice about what anyone else should do.
A certificate that reports a specification in the result column is a documentation defect, and it is a defect people should be able to recognise without it being called anything worse.
Post #43 answers the question as asked. The question underneath it is different.
One more thing on documentation that took me far too long to see: the two figures people quote are not measuring the same quantity. Once you notice that, the apparent contradiction disappears.
Patterns that reliably precede a problem: underdosing (less active material than stated, documented by independent testing), mislabelling (wrong compound, wrong strength, or wrong batch on the label), and failure to provide documentation when asked.
Documentation quality as a signal: a supplier that reports method identifiers, distinguishes specification from result, and states the counter-ion form is telling you something about systems behind the document. A certificate that is a number and a signature tells you less.
Post #50 is the version of this I will quote in future. One addition.
Reading this documentation thread as someone who came in with a fixed view: the third and seventh replies moved me and the confident ones did not.
Where I part company with post #48, and it is a narrow parting.
Nothing here should be read as an accusation against a named company, and the guidelines exist so that reports remain reports.
That is my reading. Someone else read the same page differently and was reasonable.
Whatever the answer on documentation turns out to be, the method for getting there is the same: state the assumption, do the arithmetic in public, invite the correction.
The version of documentation that I was taught turned out to be a teaching simplification. Useful, and not true in the way I had assumed it was.
Exaggerated claims without documentation: every compound has limits. No peptide is "100% pure" because purity is measured to finite precision. A supplier claiming implausible perfection without backing evidence is overreaching.
Scoping that to what I have actually seen rather than what I have read.
Post #52 put the caveat in the right place and I want to underline it.
Filing a mild objection to the consensus on documentation. Mild because I might be wrong; an objection because nobody has addressed the case that does not fit.
This is the answer, and the reason it is the answer is the more useful part.
The strongest single signal available cheaply is what happens when you ask a technical question. A quantitative answer inside a working day is difficult to fake at scale.
Practical experience of documentation, offered as one case with the conditions stated, not as a general finding. Conditions first, because they are what make it interpretable.