multiple entries with small differences

When there are 2 (or more) catalog entries which are very similar, for example a small difference in diameter (e.g., Isle of Man 50p, KM593 and KM806) or a small difference in pattern (e.g., Guernsey 1 pound, KM1091 and KM1105), there should be a note in each catalog entry describing the difference.  This would avoid swaps where the wrong coin has been cataloged and sent.

For very similar to types the main difference to distinguish them should be put into the title (more detailed in the comment section) and both pages should be cross referenced in the see also section. But this should already be in the style guide to edit the catalog. 

This may be in the style guide to edit the catalog.  I wasn't aware of that.  But my point then is that there is a failure in execution.  The lack of such comments in the 2 examples in my original post has caused mistakes in actual swaps.

I'm not sure what is not clear on first case: Isle of Man 50p, KM593 and KM806.

First one is an old one with bigger size (30mm, 13.5g). The second one is much smaller diameter (27mm, weight 8 gram) and this is clearly indicated in the title which is similar but with additional “reduced size” at the end of title.

Reference is on one page, is missing on second one (will add it soon).

There is no km# mentioned for Guernsey. 

I guess you mixed these coins with Gibraltar.

Anyway, Gibraltar coins are nicely described in titles “type 1” and “type 2” and on the second coin there is explanation in comment section what is the difference between. Both are cross-linked.

I guess, we cannot do more on these both cases. Users need to pay more attention when adding their coins to the catalogue/swap list.

The problem is that the same year, 1997, comes in both varieties.  The smaller one gets mislabeled as the big one.  There should be a warning about this possibility in the text, not just a link, especially when both varieties exist for the same year.

It's clearly written, even on the summary on the search list:

Users simply need to be more carefull when adding their coins to the collections/swaps. Also double ask if this coin is in fact the one that you need before confirming the swap. Or ask for real photos to avoid errors.

Similar for Gibraltar case, there is relevant comment on page with second type.

Anyway, feel free to write additional comments to better distinguish these coins. I will approve if there will add the value to the current coin descriptions.

OK.  I put in a warning in the entry for the Isle of Man coin.  That's what I had in mind.