Note 6 - Income Taxes - Deferred Tax Assets and Liabilities (Details) - USD ($)	Mar. 31, 2022	Mar. 31, 2021
Paid time off accrual	$ 63,055	$ 60,869
Inventory reserve	47,042	50,324
Depreciation and amortization	88,690	88,690
Stock-based compensation deductions	88,710	75,189
Unrealized gain on marketable securities, asset	89,102
Unrealized gain on marketable securities, liability		(308,403)
Other	106,870	106,869
Deferred tax assets	$ 483,469	$ 73,538

Deferred Tax Assets, Depreciation

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Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences from inventory.

+ References

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-Publisher FASB
-Name Accounting Standards Codification
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-SubTopic 10
-Section 50
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Amount after allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences and carryforwards.

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Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
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-Section 50
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Amount, before allocation of valuation allowance, of deferred tax asset attributable to deductible temporary differences, classified as other.

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Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
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Amount, before allocation of valuation allowance, of deferred tax asset attributable to deductible temporary differences from employee benefits, classified as other.

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Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences from share-based compensation.

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Amount, before allocation of valuation allowance, of deferred tax asset attributable to deductible temporary difference from unrealized loss on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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Amount of deferred tax liability attributable to taxable temporary differences from unrealized gains on trading securities.

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