When a release says '10 metres of mineralisation,' it almost always means ten metres measured down the drill core. That is only the same as the true width of the zone if the hole cut it at right angles. Drill a flat-lying or oblique zone at a shallow angle and the core length can overstate the true width by two or three times — the same tonnage, described more generously.
Honest disclosure states the relationship: 'estimated true width approximately 70% of core length,' or at least a note that true widths are not yet known. The absence of that language is itself a signal. A company confident in its geometry tells you the true width; a company leaning on a headline length often stays quiet and lets you assume core length equals thickness.
None of this makes a long intercept fake — it makes it provisional. Until true width is established, treat every reported width as an upper bound, and be most skeptical exactly where the number is doing the most promotional work.