I think "T" stands for testing.

French term (edited): BNP pg/ml 17 (T)

Natriuresis is the process of sodium excretion in the urine through the action of the kidneys.[1] It is promoted by ventricular and atrial natriuretic peptides as well as calcitonin,[2] and inhibited by chemicals such as aldosterone. Natriuresis lowers the concentration of sodium in the blood and also tends to lower blood volume because osmotic forces drag water out of the body's blood circulation and into the urine along with the sodium. Many diuretic drugs take advantage of this mechanism to treat medical conditions like hypernatremia and hypertension, which involve excess blood volume.
https://en.wikipedia.org/wiki/Natriuresis

Ventricular natriuretic peptides or brain natriuretic peptide (BNP), also known as B-type natriuretic peptide, is a hormone secreted by cardiomyocytes in the heart ventricles in response to stretching caused by increased ventricular blood volume.
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The physiologic actions of BNP are similar to those of ANP and include decrease in systemic vascular resistance and central venous pressure as well as an increase in natriuresis. The net effect of these peptides is a decrease in blood pressure due to the decrease in systemic vascular resistance and, thus, afterload. Additionally, the actions of both BNP and ANP result in a decrease in cardiac output due to an overall decrease in central venous pressure and preload as a result of the reduction in blood volume that follows natriuresis and diuresis.[3]
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Cardiac
• Inhibits maladaptive cardiac hypertrophy
• Mice lacking cardiac NPRA develop increased cardiac mass and severe fibrosis and die suddenly[10]
• Re-expression of NPRA rescues the phenotype.
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Interpretation of BNP
The main clinical utility of either BNP or NT-proBNP is that a normal level helps to rule out chronic heart failure in the emergency setting. An elevated BNP or NT-proBNP should never be used exclusively to "rule in" acute or chronic heart failure in the emergency setting due to lack of specificity[
https://en.wikipedia.org/wiki/Ventricular_natriuretic_peptid...

However, patients with treated chronic stable heart failure may have levels in the normal range (i.e., BNP less than 100 pg per mL and N-terminal proBNP less than 125 pg per mL in patients younger than 75 years)
https://www.aafp.org/afp/2006/1201/p1893.html

Some medical tests report results in picograms per millilitre (pg/mL).
https://myhealth.alberta.ca/Health/Pages/conditions.aspx?hwi...

If you have heart failure, the following NT-proBNP levels could mean your heart function is unstable:
• Higher than 450 pg/mL for patients under age 50
• Higher than 900 pg/mL for patients age 50 and older
https://my.clevelandclinic.org/health/diagnostics/16814-nt-p...

I conclude from this that BNP level of 17 pg/ml is a good indication and not worrying.

NT-proB-type Natriuretic Peptide (BNP) blood test

B-type natriuretic peptides (BNP) is a hormone produced by your heart. N-terminal (NT)-pro hormone BNP (NT-proBNP) is a non-active prohormone that is released from the same molecule that produces BNP. Both BNP and NT-proBNP are released in response to changes in pressure inside the heart.

Searching for "pg/ml (T)" relays me to testosterone

Eight men and three women received androstenedione (A4)/estrone (E1) and three men received testosterone (T)/estradiol (E2). Adipose tissue biopsies were obtained in another six men before and after CABG to evaluate levels of P450 aromatase mRNA. Serum T levels decreased postoperatively in all 17 men (P < 0.001),
https://journals.physiology.org/doi/full/10.1152/ajpendo.004...

Concentrations of testosterone (T) and 5 alpha-dihydrotestosterone (DHT) were measured in plasma collected from male and female ferrets at eight perinatal ages, spanning the period when behavioral sexual differentiation occurs in this species.
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In males, mean plasma T (2,278 pg/ml) and DHT (1,989 pg/ml) concentrations were highest on day -5, and declined significantly by postnatal day 5.
https://pubmed.ncbi.nlm.nih.gov/7106049/

Background:
Circulating testosterone (NP) levels are markedly lower in healthy men than women. A relative NP deficiency in men could contribute to their higher risk of hypertension and cardiovascular disease. Epidemiologic studies suggest testosterone may contribute to sex-specific NP differences.
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Results:
Men who did not receive testosterone replacement (placebo gel group) after suppression of endogenous gonadal steroid production experienced a profound decrease in serum testosterone (median 540 to 36 ng/dl, p

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Note added at 10 hrs (2021-06-17 12:58:47 GMT)
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Last references had been broken: I add the remainder:

p

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Note added at 11 hrs (2021-06-17 13:02:38 GMT)
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To overcome the HTML-error, I have enclose the value in quote marks:

"p

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Note added at 11 hrs (2021-06-17 13:04:00 GMT)
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Last trial I circumscribe the sign:

p below 0.0001). This was accompanied by an increase in median NT-proBNP (+8 pg/ml, p=0.02)
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6588352/

Effects of transdermal testosterone on natriuretic peptide levels in women: a randomized placebo-controlled pilot study
https://www.sciencedirect.com/science/article/abs/pii/S00150...

Obviously the "(T)" may refer to testosterone, but this assumption could be assured 100%. Hence I propose to maintain "(T)" and to refer to testosterone in a comment or footnote, if useful.


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Note added at 11 hrs (2021-06-17 13:05:05 GMT)
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Please read: could not be assured 100%