Should we normalize 'Lakh' to decimal units to make it better understood?

Question

Somebody who is using 'Lakh' as a quantity probably does not know its limited usage.

Should the diligent question editor remove 'Lakh' and multiply the quantity by 100,000 to make the question clearer to a broader audience? Or alternatively comment? Or alternatively flag?

What are the best practices for the diligent editor on the usage of 'Lakh'?

The question scope is includes the use of thousand separators for large numbers.

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Adding 22 April 2015

Summary

The consensus given by the answers below is...

1. Lahks (and implicitly crores) should be expanded into decimal units;
2. Commas should be used as the thousands separator;
3. Decimal points should be used as the fractional separator
4. Any other conversions (such as metric to imperial or fahrenheit to celsius) are not affected by this question. The question scope is limited to Lahks (and implicitly crores) only.

"So it shall be written. So it shall be done." (Rameses II)

Answer 1

I would say yes. The usage of "lakh" as a unit is fairly limited, to the Indian subcontinent. For the sake of clarity, it makes sense to convert it into a digit grouping system that's widely understood.

Informally, we've had similar discussions in comments in the past about the usage of commas versus dots in digit grouping. I don't think we have a specific stance on this; it's usually dependent on the author but we veer towards using commas instead of dots since more countries in the world use that system. (Although one could say the most populous countries use the "dot".)

Answer 2

I've personally come across Lakhs on both Stack Overflow and Travel SE. I always edit them into their base 10 representation. Whilst commas and dots for decimals are often rendered unambiguous by the context in which the number is used - 100,000 USD is clearly one-hundred-thousand dollars, rather than one-hundred-with-three-decimals dollars (as far as I know few currencies use 1e-3 precision) - Lakhs (and Crores for that matter) are features of the Indian decimal system and can therefore be confusing and/or ambiguous to those that are not familiar with them.

Answer 3

English uses comma or space as a thousands separator and period as a decimal separator. I wouldn't advocate editing posts just to change separators (unless they were causing confusion) but I would encourage people write their numbers using English orthography, given that they're writing all the words in English.

Lakhs and crores are a slightly different case. Although they are used a lot in English, that use is restricted to South Asia, a region that doesn't seem to have a lot of Stack Exchange users. Since most people on Stack Exchange don't seem to be familiar with these concepts, or the associated digit grouping scheme (e.g., 1,23,45,678) I agree with the other answers that it's probably best to avoid using lakhs and crores and to edit them away (or at least give a translation).

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In terms of actual writing style here, it's much easier to use commas than spaces as a grouping separator. If you use spaces, you have to make you don't get word-wrapping between groups, which means using some kind of non-breaking space. The standard HTML non-breaking space   is rather too wide (e.g., 1 234 567) and non-breaking thin spaces   look nice (e.g., 1 234 567) but it's hard to remember the code. Organizations that recommend spaces as separators mostly seem to recommend non-breaking thin spaces (e.g., the International Bureau of Weights and Measures, the International Union of Pure and Applied Chemistry and the American Medical Association; see references here).